teach-jove

早期freebsd实现

The describe-command command M-? will prompt for the name of a command
and print out the section from the manual about that command. When you
are finished reading it, type a Space or a C-G (quit) to bring your text
back on the screen.

>> Type C-X ? Control-P.  The message at the bottom of the screen should
   be something like "C-P is bound to previous-line".

Multi-character commands such as C-X C-C and <ESC>V are also allowed
after C-X ?.

Now lets get more information about the previous-line command.

>> Type M-? previous-line.  When you are finished reading the
   output, type a Space.

The "name of the command" is important for people who are customizing
JOVE.  It is what appears in the JOVE CHART as the documentation for
the command character.

One other form of help is the "apropos" command.  We have already tried
using this command in an earlier part of this tutorial, but it should
be mentioned again here.  Apropos prompts for a word or phrase and
lists all the commands that contain that string.  If you couldn't
remember the name of a certain command to read file, you could run the
apropos command with the keyword "file" and it would list all the
commands that contain "file".  To run apropos you would type

	M-X apr<Space>file<Return>

Finally, the full set of JOVE manuals are in five parts, and reside in the
directory /local/src/jove/doc under the names jove.1 to jove.5.  These
are in TROFF form and can be formatted into a form readable on the terminal
or line-printer with the commands:

	cd /local/src/jove/doc
	nroff -ms cmds.doc.nr jove.[1-5]

Besides, someone around you must have a printed version which you can
borrow! (There's also a copy on the Berkeley Unix 4.3 manuals - in the User
Supplementary Documents manual (the one with the green spine). There is also
a chart of JOVE commands, sorted by function, which is handy as a quick
reference. Ask your local Jove guru for a copy.

CONCLUSION OF PART TWO
----------------------
   This concludes section two of the JOVE tutorial.  The  rest  of  this
tutorial  describes  some of the very advanced features of JOVE, such as
editing more than one file at once, writing your own macros, windows, and
initialization  files.   Unless  you're  already  somewhat  familiar with
JOVE, you should probably wait a little while before starting the  third
section.

MARKS AND REGIONS
-----------------

   In  general, a command which processes an arbitrary part of the buffer
must know where to start and where to  stop.   In  JOVE,  such  commands
usually  operate  on the text between point (where the cursor is now) and
"the mark".  This range of text is called "the  region".   To  specify  a
region, you set point to one end of it and mark at the other.  It doesn't
matter which one is set first chronologically, or which one comes earlier
in the text.  Here are some commands for setting the mark:

        C-@         Set the mark where point is.
        C-<SPACE>   The same.
        C-X C-X     Interchange mark and point.

   The  most  common  way  to set the mark is with the C-@ command or the
C-<SPACE> command.  They set the mark where point is.  Then you can  move
point away, leaving the mark behind.

   Since  terminals  have  only  one cursor, there is no way for JOVE to
show you where the mark is located.  You have  to  remember.   The  usual
solution  to this problem is to set the mark and then use it soon, before
you forget where it is.  But you can see  where  the  mark  is  with  the
command  C-X  C-X which puts the mark where point was and point where the
mark was.  The extent of the region is  unchanged,  but  the  cursor  and
point are now at the previous location of the mark.

   There  are many, many commands which use regions (the area between the
point and the mark), which we have not  mentioned  here. They can be found
in the Jove Quick Reference Card.

BUFFERS
-------
   When editing a file, JOVE reads the file  into  a  buffer.   This  is
where the modifcations are done, and when you save the file with C-X C-S,
the buffer is actually written out to the file.   JOVE  permits  you  to
have  up  to 100 buffers, so, in essence, you can edit up to 100 files at
the same time.

   If you want to list the buffers you have, use  the  C-X  C-B  command.
This  will  display  a  list of the buffers, their numbers and names, and
whether or not they've been modified.

>>> Do this now, type C-X C-B.  When you're done looking, type a <SPACE>.

   You probably noticed you only have one buffer, named "Main".   If  you
were  editing  more  than one file, however, you would have more than one
buffer.  There are two ways to edit more than one file.  The first is  to
call JOVE with more than one file on the command line.  For example, the
command

			      jove a b c

would create three buffers (named Main, b, and c),  each  one  containing
one  file.   The  other  way  is  to use the C-X C-F command (called Find
File).  This command prompts you for a filename, and then reads that file
into a new buffer, and puts you into the new buffer.

   To change buffers, use the C-X B command.  JOVE will prompt you for a
buffer name, and print a name in parentheses.  If you just hit a carriage
return without typing a buffer name, you will go to the buffer named in
parentheses.  Another way to change buffers is to give C-X B a NUMBER.
This goes to the buffer NUMBER, rather than using the buffer name.

>>> Get a piece of paper, and write down the  following  commands.   Then
    run  them, to  get a feel for playing with buffers.  BE SURE TO WRITE 
    THEM DOWN! We don't want to get you lost!

			C-X C-B
			<SPACE>
			C-X C-F		(type "/etc/motd" to the prompt)
			C-X C-B
			<SPACE>
			C-X B
			<RETURN>

   Well, wasn't that fun?  Now you know how  to  get  another  file  into
another  buffer,  and then "bounce" back and forth.  A nice feature about
editing more than one file is that you can transfer text from one file to
the  other.   Just  kill  it in one file, change buffers, and then put it
back with C-Y.

WINDOWS
-------
   What you see on your screen is a "window" into the buffer you are 
editing. JOVE allows you to have more than one window on your screen, and
you can therefore look into two, or more buffers at once. You can also look at
different parts of the same file. The command C-X 2 splits your screen into
two windows, both looking into the same buffer. The command C-X 4 f will
display a specified file in the other window, C-X 4 b will display a specified
buffer in the other window, C-X n moves to the next window on the screen,
while C-X p moves to the previous window.

>>> Try the command C-X 2, which splits the screen into two windows, and
    displays the same buffer in both. You'll notice that you are in the new
    window. Try some commmands in this window, like C-V, or M-V, to move
    around in the file. Observe that the other window doesn't change its
    position relative to the buffer. This gives you a way of looking at two
    parts of the same file. 

>>> Now try to type some text, or change something. You will see the changes
    affecting the text in the other window as well. That is because both
    windows are displaying the same buffer, and therefor the same text. Changes
    in the contents of the buffer have to affect both windows.

>>> Let's now try to edit another file in this window. Give the command 
    C-X C-F and type the name of file as "/etc/motd". You now have two files
    on your screen at the same time. 

>>> Type the command M- C-V (Meta followed by C-V) and watch the other window
    page downward. This is very convenient when doing a variety of tasks, like
    correcting errors in a file - edit the file, with the list of errors in
    the other window!

>>> Finally, let's get back to the main window (with this document) by typing
    C-X p (or C-X n, since there are only two windows). Expand this window 
    to fill the entire screen by typing C-X 1. 

Enjoyable, wasn't it! There are other commands for shrinking and growing
windows, but one of the most useful when editing text like this is the command
which invokes JOVE's interactive spelling checker. It's called spell-buffer.
It runs the UNIX spell(1) command on the buffer, and puts the errors in
another buffer in another window, and allows you to edit the list to remove
the words you know are not errors. Then, type C-X C-C, which usually gets you
out of JOVE but in this case only gets you out of the spell-edit mode. You can
now go through the remaining spelling errors word-by-word, and you can correct
them. The commands for this are C-X C-N (for next error) and C-X C-P (for
previous error.) 

>>> Try the spell-buffer command now, by going M-X spel <space> and watch.
Delete a few errors, then type C-X C-C, and do a few C-X C-N's to find some
errors in this document. We've left a few ! (deliberately, of course!!!)
    

MACROS
------
   A "keyboard macro" is a command defined by the user  to  abbreviate  a
sequence  of  other commands.  If you discover that you are about to type
C-N C-D forty times, you can define a keyboard macro to do  C-N  C-D  and
call  it  with  a  repeat  count  of forty.  The commands which deal with
keyboard macros are:

        C-X (       Start defining a keyboard macro.
        C-X )       End the definition of a keyboard macro.
        C-X E       Execute the most recent keyboard macro.

   You define a keyboard macro while executing the commands which are the
definition.   Put  differently, as you are defining a keyboard macro, the
definition is being executed for the first time.  This way, you  can  see
what  the  effects of your commands are, so that you don't have to figure
them out in your head.  When you are  finished,  the  keyboard  macro  is
defined and also has been, in effect, executed once.  You can then do the
whole thing over again by invoking the macro.

   To start defining a keyboard macro, type the C-X ( command.  From then
on,  your  commands  continue to be executed, but also become part of the
definition of the macro.  "Def" appears in the mode line to remind you of
what  is  going  on.  When you are finished, the C-X ) command terminates
the definition (without becoming part of it!).

   The macro thus defined can be invoked again with  the  C-X  E  command
which  may  be  given a repeat count as a numeric argument to execute the
macro many times.  C-X ) can also be given a repeat count as an argument,
in  which  case it repeats the macro that many times right after defining
it, but defining the macro counts as the first repetition  (since  it  is
executed  as  you define it).  So, giving C-X ) an argument of 2 executes
the macro immediately one additional time.

   If  you  want  to  perform  an operation on each line, then either you
should start by positioning point on the line above the first one  to  be
processed  and  then begin the macro definition with a C-N, or you should
start on the proper line and end with a C-N.  Either way,  repeating  the
macro will operate on successive lines.

>>> Place the cursor at the top of the screen and then enter the commands
    below.  Note that after the first  command, "Def" appears in the mode 
    line.

			C-X (
			C-A
			*****
			M-F
			M-F
			M-F
			-----
			C-N
			C-X )

>>> Notice that as you typed those  commands in, they were executed.  Now   
    move  the cursor  down a couple of lines, but keep it near the top of 
    the  screen.  Type the  command C-U C-X E.  This will  execute your 
    macro 4 times.

   Although not described here, it is possible  to both name  your macros,
and to save and restore them from files.  See the documentation for this.

INITIALIZATION FILES
--------------------
   You can initialize JOVE just the way you like it by putting a file
named ".joverc" in your home directory.  To see what this file should
look like, look at the one in the directory /usr/src/local/jove/doc. The
file system.rc is one such file, the other example is example.rc. It
should be noted that the commands in this file contain control
characters, which may make it hard to read.  Use the "cat -v" command
for this. 

   To  insert control  characters into  a file with JOVE, you should use 
the C-Q command.  Type C-Q <X> where <X> is the control character. Note that
C-Q will not work on some terminals, because it, like C-S, is used for
suspending and restoring the output to the terminal. In that case, use
the command M-X quo <space> <X>. 

INTERACTIVE SHELLS
------------------

   One of JOVE's very powerful features is the ability to start up shells
within the editor, and then use shell commands within the screen editing 
environment. To execute a command again, just cursor-up to it, change it if
you want with all the normal editing keys, and hit RETURN once to bring it
down to your present command line, and again to execute it. We'll bow out
here suggesting you consult the manual for hard details, or type M-X shell
<space> if you are the adventurous type! 

CONCLUSION
----------

Remember, to exit use C-X C-C.

This tutorial is meant to be understandable to all new users, so if
you found something unclear, don't sit and blame yourself - complain to
one of the people listed at the end of this document!

You'll probably find that if you use JOVE for a few days you won't
be able to give it up.  Initially it may give you trouble.  But remember
that this is the case with any editor, especially one that can do many,
many things.  And JOVE can do practically everything.

   Hopefully you have enjoyed this tutorial,  and,  more  importantly,  I
hope you've learned something.  If you use JOVE for about a week, and be
patient, you will find that it is more convenient  and  friendly  to  use
than any other editor you've used. I know. I did.

---------------------------------------------------------------------------
This tutorial was originally written by Richard Stallman for EMACS and
modified by Doug Kingston and Jonathan Payne for JOVE. The section on windows
was added by Mark Moraes.  Comments on this document should be sent to
[e-mail] or to [e-mail].