4.3BSD/usr/contrib/jove/doc/teach-jove
You are looking at the JOVE tutorial. This was written by Richard Stallman
and modified by Doug Kingston and Jonathan Payne. Comments on this document
should be sent to payne@rochester. (12 February '86)
JOVE commands generally involve the CONTROL key (sometimes labelled
CTRL or CTL) or the META key (generally labelled ESCAPE). Rather than
write out META or CONTROL each time we want you to prefix a character,
we'll use the following abbreviations:
C-<chr> means hold the CONTROL key while typing the character <chr>
Thus, C-F would be: hold the CONTROL key and type F.
M-<chr> means type the META (ESCAPE) key and release it, then type
the character <chr>. The <chr> can be upper or lower case
and it will have the same meaning.
Important note: if you must exit at some point, type C-X C-C.
The characters ">>" at the left margin indicate directions for you to
try using a command. For instance:
>> Now type C-V (View next screen) to move to the next screen.
(go ahead, do it by depressing the control key and V together).
From now on, you'll be expected to do this whenever you finish
reading the screen.
Note that there is an overlap when going from screen to screen; this
provides some continuity when moving through the file.
The first thing that you need to know is how to move around from
place to place in the file. You already know how to move forward a
screen, with C-V. To move backwards a screen, type M-V (depress the
META key and type V, or type <ESC>V if you don't have a META or EDIT
key).
>> Try typing M-V and then C-V to move back and forth a few times.
SUMMARY
-------
The following commands are useful for viewing screenfuls:
C-V Move forward one screenful
M-V Move backward one screenful
C-L Center the current line--clear screen and redisplay
everything if current line is already at center.
>> find the cursor and remember what text is near it.
Then type a C-L.
Find the cursor again and see what text is near it now.
BASIC CURSOR CONTROL
--------------------
Getting from screenful to screenful is useful, but how do you
reposition yourself within a given screen to a specific place? There
are several ways you can do this. One way (not the best, but the most
basic) is to use the commands previous, backward, forward and next.
As you can imagine these commands (which are given to JOVE as C-P,
C-B, C-F, and C-N respectively) move the cursor from where it
currently is to a new place in the given direction. Here, in a more
graphical form are the commands:
Previous line, C-P
:
:
Backward, C-B .... Current cursor position .... Forward, C-F
:
:
Next line, C-N
You'll probably find it easy to think of these by letter. P for
previous, N for next, B for backward and F for forward. These are the
basic cursor positioning commands and you'll be using them ALL the
time so it would be of great benefit if you learn them now.
>> Do a few C-N's to bring the cursor down to this line.
>> Move into the line with C-F's and then up with several C-P's. See
what C-P does when the cursor is in the middle of the line.
Lines are separated by a single Linefeed character, which is what Unix
calls a Newline.
>> Try to C-B at the beginning of a line. Do a few more C-B's.
Then do C-F's back to the end of the line and beyond.
When you go off the top or bottom of the screen, the text beyond the
edge is shifted onto the screen so that your instructions can be
carried out while keeping the cursor on the screen.
>> Try to move the cursor off the bottom of the screen with C-N and
see what happens.
If moving by characters is too slow, you can move by words. M-F
(Meta-F) moves forward a word and M-B moves back a word.
>> Type a few M-F's and M-B's. Intersperse them with C-F's and C-B's.
Notice the parallel between C-F and C-B on the one hand, and M-F and
M-B on the other hand. Very often Meta characters are used for
operations related to English text whereas Control characters operate
on the basic textual units that are independent of what you are
editing (characters, lines, etc). There is a similar parallel between
lines and sentences: C-A and C-E move to the beginning or end of a
line, and M-A and M-E move to the beginning or end of a sentence.
>> Try a couple of C-A's, and then a couple of C-E's.
Try a couple of M-A's, and then a couple of M-E's.
See how repeated C-A's do nothing, but repeated M-A's keep moving
farther. Do you think that this is right?
Two other simple cursor motion commands are M-< (Meta Less-than),
which moves to the beginning of the file, and M-> (Meta Greater-than),
which moves to the end of the file. You probably don't need to try
them, since finding this spot again will be boring. If you need the
shift key to type a "<", then you must also use the shift key to type
M-<. Otherwise, you would be typing M-, .
The location of the cursor in the text is also called "point". To
paraphrase, the cursor shows on the screen where point is located in
the text.
Here is a summary of simple moving operations including the word and
sentence moving commands:
C-F Move forward a character
C-B Move backward a character
M-F Move forward a word
M-B Move backward a word
C-N Move to next line
C-P Move to previous line
C-A Move to beginning of line
C-E Move to end of line
M-A Move back to beginning of sentence
M-E Move forward to end of sentence
M-< Go to beginning of file
M-> Go to end of file
>> Try all of these commands now a few times for practice. Since the
last two will take you away from this screen, you can come back
here with the command C-X C-X (which will be explained later).
These are the most often used commands.
Like all other commands in JOVE, these commands can be given arguments
which cause them to be executed repeatedly. The way you give a
command a repeat count is by typing META and then the digits before
you type the command. (Remember META is ususally called ESCAPE)
For instance, META 8 C-F moves forward eight characters.
>> Try giving a suitable argument to C-N or C-P to come as close
as you can to this line in one jump.
The only apparent exception to this is the screen moving commands, C-V
and M-V. When given an argument, they scroll the screen up or down by
that many lines, rather than screenfuls. This proves to be much more
useful.
>> Try typing M-8 C-V now.
Did it scroll the screen up by 8 lines? If you would like to scroll
it down you can give an argument to M-V.
QUITTING FROM COMMANDS
----------------------
The character in JOVE used to quit out of all commands which request
input is C-G. For example, you can use C-G to discard a numeric
argument or the beginning of a command that you don't want to finish.
>> Type M-100 to make a numeric arg of 100, then type C-G. Now type
C-F. How many characters does it move? If you have typed an <ESC>
by mistake, you can get rid of it with a C-G.
ERRORS
------
Sometimes you may do something which JOVE doesn't allow. If it is
something simple, such as typing a control key sequence which is not
associated with any command, JOVE will just beep at you. Otherwise,
JOVE will also display an informative error message at the bottom of
the screen.
Some versions of JOVE do not have all the features described in this
tutorial implemented yet. If you come across such an unimplemented
feature, you may get an error message when you try to use it. Just
proceed on to the next section of the tutorial.
INSERTING AND DELETING
----------------------
If you want to type text, just do it. Characters which you can see,
such as A, 7, *, etc. are taken by JOVE as text and inserted
immediately. Type <Return> (the carriage-return key) to insert a line
separator.
You can delete the last character you typed by typing <Delete>.
<Delete> is a key on the keyboard, which may be labeled "Rubout"
instead of "Delete" on some terminals. More generally, <Delete>
deletes the character immediately before the current cursor position.
>> Do this now, type a few characters and then delete them by typing
<Delete> a few times. Don't worry about this file being changed;
you won't affect the master tutorial. This is just a copy of it.
>> Now start typing text until you reach the right margin, and keep
typing. When a line of text gets too big for one line on the
screen, the line of text is "continued" off the edge of the screen
The exclamation mark at the right margin indicates a line which has
been continued. The line will slide over if you move off the edge
on either side.
>> The following line actually goes off the edge. Trying typing enough
C-F's that you move off the right hand end of this line.... This is a long line of text that the JOVE editor extends to the right.
>> Use <Delete>s to delete the text until the line fits on one screen
line again. The continuation "!" will go away.
>> Move the cursor to the beginning of a line and type <Delete>. This
deletes the line separator before the line and merges the line onto
the previous line. The resulting line may be too long to fit, in
which case it has a continuation indication.
>> Type <Return> to insert the separator again.
Remember that most JOVE commands can be given a repeat count; Note
that this includes characters which insert themselves.
>> Try that now -- type META 8 * and see what happens.
If you want to create a blank line in between two lines, move to the
second of the two lines and type C-O.
>> Try moving to a line and typing C-O now.
You've now learned the most basic way of typing something in JOVE and
correcting errors. You can delete by words or lines as well. Here is
a summary of the delete operations:
<Delete> delete the character just before the cursor
C-D delete the next character after the cursor
M-<Delete> kill the word immediately before the cursor
M-D kill the next word after the cursor
C-K kill from the cursor position to end of line
M-K kill to the end of the current sentence
Notice that <Delete> and C-D vs M-<Delete> and M-D extend the parallel
started by C-F and M-F (well, <Delete> isn't really a control
character, but let's not worry about that). C-K and M-K are like C-E
and M-E, sort of, in that lines are opposite sentences.
Now suppose you kill something, and then you decide that you want to
get it back? Well, whenever you kill something bigger than a
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.
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.
TEXT REPLACEMENT
---- -----------
>> 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 occurance 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 occurances without asking further. It is
described in detail in the JOVE manual.
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.
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...
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-Z 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>
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!
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.