teach-jove

早期freebsd实现

character, JOVE saves it for you.  To yank it back, use C-Y.  Note
that you don't have to be in the same place to do C-Y; This is a good
way to move text around.  Also note that the difference between
"Killing" and "Deleting" something is that "Killed" things can be
yanked back, and "Deleted" things cannot.  Generally, the commands
that can destroy a lot of text save it, while the ones that attack
only one character, or nothing but blank lines and spaces, do not save.

For instance, type C-N a couple times to postion the cursor at some
line on this screen.

>> Do this now, move the cursor and kill that line with C-K.

Note that a single C-K kills the contents of the line, and a second
C-K kills the line itself, and make all the other lines move up.  If
you give C-K a repeat count, it kills that many lines AND their
contents.

The text that has just disappeared is saved so that you can retrieve
it.  To retrieve the last killed text and put it where the cursor
currently is, type C-Y.

>> Try it; type C-Y to yank the text back.

Think of C-Y as if you were yanking something back that someone took
away from you.  Notice that if you do several C-K's in a row the text
that is killed is all saved together so that one C-Y will yank all of
the lines.

>> Do this now, type C-K several times.

Now to retrieve that killed text:

>> Type C-Y.  Then move the cursor down a few lines and type C-Y
   again.  You now see how to copy some text.

What do you do if you have some text you want to yank back, and then
you kill something else?  C-Y would yank the more recent kill.  But
the previous text is not lost.  You can get back to it using the M-Y
command.  After you have done C-Y to get the most recent kill, typing
M-Y replaces that yanked text with the previous kill.  Typing M-Y
again and again brings in earlier and earlier kills.  When you have
reached the text you are looking for, you can just go away and leave
it there.  If you M-Y enough times, you come back to the starting
point (the most recent kill).

>> Kill a line, move around, kill another line.  Then do C-Y to get
   back the second killed line.  Then do M-Y and it will be replaced
   by the first killed line.  Do more M-Y's and see what you get.
   Keep doing them until the second kill line comes back, and then a
   few more.  If you like, you can try giving M-Y positive and negative
   arguments.


FILES
-----

In order to make the text you edit permanent, you must put it in a
file.  Otherwise, it will go away when your invocation of JOVE goes
away.  While you are editing a file in JOVE, your changes are actually
being made to a private "scratch" copy of the file.  However, the
changes still don't become permanent until you "save" the file.  This
is so you can have control to avoid leaving a half-changed file around
when you don't want to.

If you look near the botton of the screen you will see a line that
looks like this:
    JOVE (Text) Buffer: teach-jove "teach-jove" *
"teach-jove" is the name of the file you are editing.  This is the name
of your own temporary copy of the text of the JOVE tutorial; the file
you are now editing.  Whatever file you edit, that file's name will
appear in that precise spot.

The commands for finding and saving files are unlike the other
commands you have learned in that they consist of two characters.
They both start with the character Control-X.  There is a whole series
of commands that start with Control-X; many of them have to do with
files, buffers, and related things, and all of them consist of
Control-X followed by some other character.  As with M- the character
interpreted the same regardless of case.

Another thing about the command for finding a file is that you have to
say what file name you want.  We say the command "reads an argument
from the terminal" (in this case, the argument is the name of the
file).  After you type the command

	C-X C-F   Find a file

JOVE will ask you for the file name.  You should end the name with
the Return key.  After this command, you will see the contents of the
file in your JOVE.  You can edit the contents.  When you wish to make
the changes permanent, issue the command

	C-X C-S   Save the file

Warning: on many systems JOVE will not be able to process the key C-S.
In place of C-S, you should type C-\.  It is possible to make C-S work
but C-\ is guaranteed always to work in place of C-S.

The old version of the file will be replaced.  When the operation is
finished, JOVE prints the name and number of lines and characters
saved.

If you forget to save and then edit a different file, JOVE will remind
you that you made changes that have not been saved and then ask you
whether you really want to quit.  (If you don't save them, they will
be thrown away.  That might be what you want!)  You should answer with
a "Y" to throw the changes away or "N" to abort quitting so you can
then save the changes.

To make a new file, just edit it "as if" it already existed.  Then
start typing in the text.  When you ask to "save" the file, JOVE will
really create the file with the text that you have inserted.  From
then on, you can consider yourself to be editing an already existing
file.

It is not easy for you to try out editing a file and continue with the
tutorial.  But you can always come back into the tutorial by starting
it over and skipping forward.  So, when you feel ready, you should try
editing a file named "FOO", putting some text in it, and saving it;
then exit from JOVE and look at the file to be sure that it worked.

CONCLUSION OF PART ONE
----------------------
   This is the end of the first part of  this  tutorial.   You  now  know
enough to edit a file with JOVE, and save your work.  The second part of
this tutorial, which starts with the next section,  discusses  searching,
replacing,  word  processing,  and other modes of JOVE.  You may wish to
stop here and practice for awhile before you continue.


EXTENDING THE COMMAND SET
-------------------------

There are many, many more JOVE commands than could possibly be put on
all the control and meta characters.  JOVE gets around this with the X
(eXtend) command.  This comes in two flavors:

	C-X	Character eXtend.  Followed by one character.
	M-X	Named command eXtend.  Followed by a long name.

These are commands that are generally useful but used less than the
commands you have already learned about.  You have already seen two of
them: the file commands C-X C-F to Find and C-X C-S to Save.  Another
example is the command to tell JOVE that you'd like to stop editing.
The command to do this is C-X C-C.

There are many C-X commands.  The ones you need immediately are:

	C-X C-V		Visit file.
	C-X C-S		Save file.
	C-X C-C		Quit JOVE.  This does not save your files auto-
			matically, though if your files have been modi-
			fied, JOVE asks if you really want to quit.  The
			standard way to save and exit is C-X C-S C-X C-C.

Named eXtended commands are commands which are used even less
frequently, or commands which are used only in certain modes.  These
commands are usually called "commands".  An example is the command
"apropos", which prompts for a keyword and then gives the names of all
the commands that apropos for that keyword.  When you type M-X, JOVE
prompts you at the bottom of the screen with ":" and you should type
the name of the command you wish to call; in this case, "apropos".
Just type "apr<Space>" and JOVE will complete the name.  JOVE will ask
you for a keyword or phrase and you type the string that you want ask
about.

>> Try typing M-X, followed by "apropos" or "apr" and then Return.
   Then try typing "file" followed by a Return.


MODE LINE
---------

If JOVE sees that you are typing commands slowly it shows them to you
at the bottom of the screen in an area called the echo area.  The echo
area contains the bottom line of the screen.  The line immediately above
them is called the MODE LINE.  The mode line says something like

   JOVE (Text)  Buffer: [buffername]  "filename" *

This is a very useful "information" line.

The buffername is the name JOVE gave to the buffer, and it is usually
related to the filename.  You already know what the filename means --
it is the file you have edited.

The star means that you have made changes to the text.  Right after
you visit or save a file, there is no star.

The part of the mode line inside the parentheses is to tell you what
modes you are in.  The default mode is Text which is what you are in
now.  It is an example of a "major mode".  There are several major
modes in JOVE for editing different languages and text, such as C
mode, Lisp mode, Text mode, etc.  At any time one and only one major
mode is active, and its two-letter code can always be found in the
mode line just where "Text" is now.  Each major mode makes a few
commands behave differently.  For example, what JOVE considers as part
of a valid expression or an identifier differs from one major mode to
another, since each programming language has a different idea of what
is a legal identifier.

Major modes are called major because there are also minor modes.  They
are called minor because they aren't alternatives to the major modes,
just minor modifications of them.  Each minor mode can be turned on or
off by itself, regardless of what major mode you are in, and
regardless of the other minor modes.  So you can use no minor modes,
or one minor mode, or any combination of several minor modes.

One minor mode which is very useful, especially for editing English
text, is "Auto Fill" mode.  When this mode is on, JOVE breaks the line
in between words automatically whenever the line gets too long.  You
can turn this mode on by doing M-X auto-fill-mode<Return>.  When the
mode is on, you can turn it off by doing M-X auto-fill-mode<Return>--
it toggles.

>> Type "M-X auto-fill-mode<Return>" now.  Then insert a line with a
   bunch of words over again until you see it divide into two lines.
   You must put in spaces between them because Auto Fill breaks lines
   only at spaces.  Notice that "Fill" (the code for Auto Fill) appears
   in the mode line after "Text" to indicate that you are in Text Fill
   mode.

The margin is usually set at 78 characters, but you can change it with
the set command.  The margin is kept in a variable just like the mode
values.

>> Type "M-X set right-margin 20", then type in some text and see
   JOVE fill lines of 20 characters with it.  Then set the margin
   back to 72 using M-X set again.


SEARCHING
---------

JOVE can do searches for strings (these are groups of contiguous
characters or words) either forward through the file or backward
through it.  To search for the string means that you are trying to
find that string somewhere in the file.  Remember to use C-\ where it
says C-S.

>> Now type C-S to start a search.  Type the word 'cursor', then
   Return.

>> Type C-S Return to find the next occurrence of "cursor".

The C-S starts a search that looks for any occurrence of the search
string AFTER the current cursor position.  But what if you want to
search for something earlier in the text?  To do this one should type
C-R for reverse search.  Everything that applies to C-S applies to C-R
except that the direction of the search is reversed.


REPLACING TEXT
--------------

>> Move the cursor to the blank line two lines below this one.
   Then type M-r changed<Return>altered<Return>.

   Notice how this line has changed: you've replaced the word
   c-h-a-n-g-e-d with "altered" wherever it occurs after the cursor.

The more customary command for replacing strings is the interactive
command query-replace-search, which has several options.  In essence,
it shows each occurrence of the first string and asks you if you want to
replace it or not.  You can also choose to edit around the string, or
go on and replace all occurrences without asking further.

   This is invoked with M-Q..  When you start up a Query Replace, it
will prompt you with "From" and "To", for what you want to change, and
what you want to change it to.  JOVE will then move to the first
occurence of the "From", and wait for a character.  You can type:

	<SPACE>		Do  the  replacement, and move to next occurrence
			of the "From" string.
	<DEL>		Skip  the  current  "From" string and move to the 
			next one.
	RETURN		Exit the Query Replace now.
	r		Recursive Edit
	p		Replace  all  further  occurences  of  the "From" 
			string,	without asking. 

Recursive edit makes it possible to temporarily supend the Q-R-S, let the
user go off and do something, and then return to the search after the  he
is done. The command exit-jove (C-X C-C) returns from the recursive-edit.

GETTING MORE HELP
-----------------

In this tutorial we have tried to supply just enough information to
get you started using JOVE.  There is so much available in JOVE that
it would be impossible to explain it all here.  However, you may want
to learn more about JOVE since it has numerous desirable features that
you don't know about yet.  JOVE has a some internal documentation.

The most basic HELP feature is the describe-key command which is
available by typing C-X ? and then a command character. JOVE prints
one line line on the bottom of the screen tell what command is bound to
that key.  You can then get further information on that command
using...