Power Programming/powerprogramming1994.iso/progtool/editor/tvx_edit.arc/TVX_REF1.DOC

Text File | 1986-03-17 | 58KB | 1,387 lines

                         TVX Reference Manual



     This is the Reference Manual for TVX, a full screen
editor written in C by Dr. Bruce E. Wampler.  (Current address: Dr.
Bruce E. Wampler, University of New Mexico, Department of Computer
Science, Farris Engineering Center, Albuquerque, NM 87131; uucp:
...{ucbvax | gatech | ihnp4!lanl}!unmvax!wampler).  Any comments, bug
reports, or suggestions should be sent to that address.  The name TVX
is derived from "TV" editor for any terminal ("X").

     The current release of TVX has several different versions:

1) Standard TVX - The original version and command set of TVX.
2) VIX - A version of TVX that emulates the Unix vi editor.
3) TVX0 - A modeless version of TVX.
4) EMAX - A version of TVX that emulates the EMACS editor.

     The main part of this manual is written describing "Standard
TVX," the version used by the author.  The VIX, TVX0, and EMAX
versions are described in appendices.  While the emulator versions of
TVX are close command set compatible versions of the original editors,
the you should be aware that certain fundamental properties of the
underlying TVX editor remain, and that the emulators will not work
exactly like the originals.  If you intend to use one of the other
versions of TVX, you should read this part of the manual up to the
section describing standard TVX commands first.


*** General Comments ***

     Standard TVX functions almost identically for all versions,
including the command set.  The emulation versions of TVX have been
written to be command set compatible with the original versions of the
editors.  It is also possible to construct a completely new version of
TVX with a custom command set.  Control codes on are normally entered
by pressing the CTRL key and the letter key at the same time.  On most
versions, the character delete key is BACKSPACE.  This character
delete key is the one normally used by the respective operating
system.  It is up to the local implementation to notify the user of
any variance from these conventions.

     Once the file has been read in, the screen will be cleared, and
the first screenful of the file printed on the screen and the cursor
positioned over the first character of the file.  If a new file is
being created, the message "buffer empty" will be displayed, and the
cursor positioned in the upper left corner.  TVX is then ready to
accept commands from the keyboard.  TVX works on the principle that
what you see is what you get.  Most commands also take an optional
numeric count.  The default count is always one.  Commands that allow
a count value are preceded by the letter 'n' in the following
descriptions.  Whenever a command produces output or an error message,
it appears on the bottom line of the screen.

     The BACKSPACE key (Control-H on some terminals) is used to edit


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input text.  When TVX is accepting commands, BACKSPACE will cause the
character immediately before the cursor to be deleted.

     TVX (all versions!) works entirely in the available memory for
editing.  The text from the file which is being edited is held in a
buffer in main memory.  If a file is particularly large, it may not
entirely fit into main memory.  The MS-DOS versions, for example, will
allow about 50K characters, depending on the memory available.  Unix
versions will usually allow 120,000 characters and 5000 lines in one
buffer.  If the entire file will not fit into the buffer at once, then
only part of it is read in at a time.  The buffer size limit in no way
restricts the total size of a file that can be edited by TVX.  To make
editing large files easier, some commands apply to the entire file and
cause automatic cross buffer manipulation.

     Because of the internal organization of the text within the
buffer, TVX may occasionally "compact" the tiny fragments of unused
buffer space generated as a part of normal editing.  When this
happens, a message is displayed, and input keystrokes are remembered
but not echoed until the compaction process is complete.  The process
may take several seconds.

     TVX actually divides the internal memory into two parts: the text
buffer and the save buffer.  The text buffer (or simply the buffer) is
used to hold the file (or part of the file) being edited.  There is
only one such text buffer (unlike some other editors such as emacs).
The save buffer is used for moving text, both from one part of the
text buffer to the other, as well as to and from external files.  The
maximum size of the save buffer depends on the amount of text
currently residing in the main text buffer.  The following diagram
shows the internal TVX memory organization:

   +-----------------------------+
   |  TEXT BUFFER - the current  |
   |  text (or portion) of file  |
   |  being edited. (grows down) |
   |            _________________|
   |___________|                 |
   |  free memory        ________|
   |_____________________|       |
   |  SAVE BUFFER - grows up     |
   +-----------------------------+

     Text is added to the text buffer when the file is first read in
(or created).  If the file doesn't fit into one buffer, you will have
to manually "page" the text into the buffer.  Text is added to the
save buffer in one of several ways.  TVX (and emulators) have commands
to move text from the text buffer to the save buffer, and move the
contents of the save buffer to the text buffer.  TVX also has "cut
mode".  When cut mode is enabled, when lines are killed, they are
automatically copied into the save buffer as well as being deleted
from the text buffer.  Cut mode is normally off for TVX, but is on for
VIX and EMAX.  It is also possible to save the contents of the save
buffer to a new external file, and to load the save buffer from an
external file.  All versions of TVX use this scheme for handling
text.


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     End of lines are not special to TVX.  Thus all the cursor
movement commands and delete single character commands will treat the
end of line as just another character.  This also means that a
<Return> (end of line) is a valid search character, and thus makes it
impossible to end a find pattern with a <Return>.  The <Escape> key is
used to mark the end of a find pattern.  All the Standard TVX wild
cards may be used for all versions of TVX.

     Another basic concept of TVX is the "last thing." Whenever TVX
finds a pattern from the search command, skips over a word, or gets
from or puts to the save buffer, that text is considered the "last
thing." All versions of TVX will have a command that can delete the
last thing.  While this is this a powerful editing concept, it does
have some consequences.  First, the cursor will always be placed AFTER
the pattern just found.  It also means that TVX has no delete word
commands.  Instead, the delete last thing command is used after
skipping over a word.  Using the delete last thing also makes it very
easy to save text into the save buffer, and then deleting it after the
desired number of lines have been saved.

     Probably the most powerful editing tool provided by TVX is the
repeat loop.  This allows arbitrary command sequences to be entered,
and repeated any number of times.  All versions of TVX will have at
least 5 different repeat buffers.  All emulation versions of TVX use
the basic TVX repeat loop instead of emulating whatever macro facility
might be provided by the orignal editor.  (The commands inside the
repeat loop are the emulated commands, not standard TVX commands.)

     Many of the basic operating characteristics of TVX are
controllable by user settable parameters.  These parameters are
relevant to all versions of TVX, with the current status of each
displayed on the help screen.  These parameters are summarized in the
'set parameter' command (':') in the Standard TVX Commands section,
but a brief overview of the paramaters will also cover some of the
capabilities of TVX (and the emulator versions).

     While the normal screen is only 80 columns wide, TVX has been
written to support a "virtual" screen width of 240 columns.  As you
move the cursor right on a line that is longer than 80 columns, the
screen will automatically scroll to the left in increments of 16
columns.  You can also control how many lines of the screen TVX uses
using the 'v' parameter.  Normally, TVX will use the entire screen.
If you are working over phone lines, you can tell TVX to use only 5 or
7 lines, thus making updating much faster.

     TVX has some limited word processing cabability.  This is the
autowrap feature, settable both when you first run TVX, and by the 'w'
parameter.  Setting autowrap to column 65, for example, will tell TVX
to automatically insert a newline whenever you enter text past that
column.  The 'tidy' command will use the autowrap margin to 'fill' the
text after the fact.  This feature makes it easy to make your text
more readable, and even create good looking short memos without
needing to resort to nroff or troff.

     For programmers, TVX has an autowrap command.  The 'a' parameter
controls this feature.  When enabled, TVX will automatically match the


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leading white space at the beginning of the previous line.

     The search command also has some advanced features.  By default,
searches are case insensitive, but the 'f' parameter controls this.
TVX also supports a set of "wild cards".  You can specify a set of
letters, numbers, alphanumerics, punctuation, or other characters as
part of the wild cards.  The 'u' parameter also allows you to define
your own set of wild card characters.  TVX remembers the last pattern
found (the actual pattern, not just the wild cards), and has a command
to insert that pattern into the text.  Thus, with repeat loops, wild
cards, and the insert found pattern command, it is possible to do
quite creative editing functions.  The 'm' parameter controls the use
of wild card matching, so it can be disabled if you need to match one
of the wild card characters.

     Finally, TVX has parameters to control just how the screen is
scrolled.  The home display line controlled by the 'd' parameter tells
TVX which line to put the cursor on when the screen has been
'verified'.  The 's' scroll window controls how many lines the cursor
will move up and down from the home line before scrolling the text.
If the scroll window is 0, then the cursor will be fixed on the home
display line.  By setting it to another value, you can control how
much context remains before scrolling.  These settings are very much
personal taste.

     TVX uses two techniques for protecting the original file from
editing mistakes.  First, each time a file is edited, a new version is
created, and the previous version retained in its original form as a
backup.  This file will change the original file extension to '.BAK'
on MS-DOS systems, and '.B' on Unix.  A more complete description of
TVX file handling is included in an appendix.  Also, as you edit your
file, TVX has the capability to write all commands entered during the
session to a log file when that capability is enabled.  In the event
of a major editing mistake, it is possible to edit that log file to
remove the command errors, and then apply that "command" file to the
previous version of the edited file to get back to the state right
before the mistake.  This feature also allows files of TVX commands to
be defined by the user and executed in one step.  The last section of
the Reference Manual explains how to use the command file feature.



*** RUNNING THE EDITOR ***

     To edit a file using TVX, enter the following command line:

          tvx filename -switch1 -switch2 ...

     (VIX, EMAX, and TVX0 use the SAME command line format and
switches.) The file name specified is the file to be edited, and must
obey the conventions used by the local operating system (the MS-DOS
version requires DOS version 2.0, and supports pathnames).  If the
file is a new file (does not exist), TVX will ask if you really want
to create it.  Answer y or n. If you gave an incorrect name, you may
give the correct name, but the switches entered on the original start
line will remain in effect.  Control-C can be used at this point to


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abort.

     TVX has several switches which control certain operating
characteristics.  Each switch begins with a minus (-), and is
separated from the file name and other switches by a blank in the
standard UNIX/C convention.  Some switches may be negated by using a
'nox' form.  Thus, '-b' will cause a .bak file to be generated, while
a '-nob' causes the .bak file to be deleted on exit from the editor.
This capability is indicated by []'s.  As many switches as necessary
or desired can be used at one time in any order.  A ':' may be used
instead of a '=' for '-c' and '-o'.  The various switches supported
include:

     -c=filename -- read a configuration file.  If only -c is
          specified, TVX will look for file called /bin/CONFIG.TVX on
          MS-DOS, for example.  The -c switch is not supported on all
          implementations.
     -[no]b -- generate a .B[AK] version of the original (the usual
          default).  The -nob option means no .BAK file is generated.
          This latter mode of operation follows the normal Unix
          convention of not keeping past generations of a file.
     -[no]i -- auto indent mode enabled.
     -[no]l -- generate BACKUP.LOG file
     -o=filename -- send edited output to filename.  The output file
          can also be changed at any time during the editing session
          with the ':o' command.
     -r -- read only - file can be read in only
     -s -- big save buffer - leaves more buffer for save file
     -t -- tty mode - puts TVX into tty mode, not using the screen.
          See the special appendix on tty mode.  (This is supported
          only by two mode versions of TVX.)
     -w -- word processing mode - sets autowrap on, margin to 65.
     -z -- -z means use Control-Z to mark end of file, -noz means
          don't use.  This switch is used only on MS-DOS
          implementations.
     -# -- entering a number from 3 up to the number of lines on the
          screen will create a smaller TVX editing window.  This is
          most useful for slower baud rates.  A -7 makes a nice, small
          window showing 7 lines.

     TVX is mostly a programmer's editor, and can can edit any
standard text line file.  On Unix systems, it is an alternative to
standard editors such as ed or vi.















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               *** Summary of Standard TVX Commands ***



     A key to success when using TVX is to remember that there are two
modes of operation.  The normal mode is command mode.  In this mode,
all keystrokes are interpreted as commands.  When you want to enter
text, you must enter insert mode with the 'I' command.  While in
insert mode, all keystrokes entered will be inserted into the file and
displayed on the screen.  You must exit from insert mode with the
escape key.  When you enter insert mode, the message "### Insert Mode
###" will be displayed on the last line of the display.  Also, on many
terminals, TVX will change the cursor shape between command and insert
mode.

     The modeless version of TVX (TVX0) uses the same mnemonics as
Standard TVX for the most part.  There is a 1:1 mapping between the
commands.  The modeless names for each command is included in each
description of Standard TVX commands.  Counts for any modeless TVX
command can be entered after the escape.  Thus, "<Esc>10K" will kill
ten lines, while <Esc>10^K" will kill 10 characters.

     Notes: An n preceding a command means optional numeric
     argument may be supplied.  If omitted n will default to 1,
     and n can be zero or negative if appropriate.  '$'
     represents the escape key, and is used as a terminator for
     insert, find, and loops.  Control commands are indicated
     with '^'.  For example, '^K' represents Control-K, and is
     usually entered by simultaneously holding down the CTRL key
     and the K key.


nA - Append to Save Buffer

     The 'A' command is used to append lines of text to the end of the
save buffer, even if other commands have been used since the last 'A'
or 'S' command.  The append command works exactly like the 'S' command
otherwise.


B - Buffer beginning {TVX0: ^B}

     A 'B' causes the cursor to be moved to the beginning of the
current buffer.


^B - Beginning of file {<Esc>B}

     The '^B' (Control-B) command is used to position the cursor to
the absolute beginning of the file.  The '^B' command will always
write out the rest of the file, then re-read the first buffer full.
This command has the side effect of making a new backup version of the
file.  It should be noted that any text saved in the save buffer will
be preserved during this operation, so that the 'S' save command can
be used to move text from the end to the beginning of a multi-buffer
file.  The search pattern and repeat loops are retained as well.  Note


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the '^B' file beginning is similar in concept to 'B' buffer
beginning.


nC - Change {^C}

     'C' can be used to change characters.  Entering 'nC' is exactly
equivalent to entering 'nKI'.  The command will cause 'n' characters
to be killed, and insert mode to be entered.  The escape must be used
to terminate the insert as usual.


nD - Down {^D}

     'D' moves the cursor down n lines.  The cursor is placed at the
beginning of the new line.  For convenience, the ENTER key performs
the identical function.


n^D - Down in column {<Esc>D}

     Control-D ('^D') is similar to 'D', except the cursor remains in
the original column.  Columns are defined as characters from the
beginning of the line, so if a line has tab characters in it, the
cursor may appear to move out of column on the screen.


E - End of the buffer {^E}

     'E' causes the cursor to be placed at the end of the current text
buffer.


n^E - Edit repeat buffer n {<Esc>E}

     When making repeat loops, it is easy to make a mistake.  The ^E
command allows any of the repeat buffers to be edited, and then the ^R
command can save the corrected repeat buffer back.  If you don't give
a value for n, the currently selected buffer is used.  If n is from 1
to the maximum number of repeat buffers, then that repeat buffer will
be selected for editing.

     The ^E command will insert the contents of the selected repeat
buffer into the current text buffer.  The repeat buffer will be
inserted above the current text line.  The repeat buffer will start
with a sequence of '#n:<', where n will be replaced by the repeat
buffer being edited.  The '#n:' identifies which buffer you are
editing, and is used by the ^R store repeat buffer command to identify
the buffer to save to.  Escapes will be represented by '^[' instead of
the '$' used when entering a repeat buffer initially.  A '>^[^['
identifies the end of the repeat loop.

     It is possible to make as many changes as needed to the repeat
loop.  Escapes can be added by using '27i'.  If you want to save the
loop in a different buffer, you can change the number after the '#'.
It is also important to maintain the '#n:<' start and '>^[^[' ending


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sequences.  Also, loops are limited to a maximum of 100 characters.
You can have carriage returns within the body of a loop, too.  If you
want to create a new buffer, you can use ^E on an empty repeat buffer
to get the required '#n:<>^[^[' loop sequence.

     After you have edited the repeat buffer, it can be saved with the
'^R' command.  You must place the cursor anywhere on the first line of
the repeat buffer before using '^R'.  When you press ^R, the buffer
will be saved in the buffer indicated right after the '#'.  Thus,
unlike ^E, the ^R command accepts no n value.


nF - Find text pattern {^F}

     'F' is used to find a text pattern.  When 'F' is entered, the
message 'Find?' is echoed on the bottom line.  You then enter the
pattern to find, terminated with the escape key (echoed as $).  When
the count 'n' is positive (which is the default), find searches the
current buffer from the current position forward.  If 'n' is negative,
then a backwards search is performed starting with the previous line.
(Use '^F' to search across buffers).  Normally, 'F' ignores the case
of the letters in the pattern.  If the ':F' parameter is set with 0,
then 'F' command will match only the exact case.  See the ':' set
parameter command for details of the ':F' parameter.  If the pattern
is not found, "Not found" will be printed and the cursor remain at its
original location.  If the pattern is found, then the cursor will be
placed immediately following the pattern.  The pattern may be at most
100 characters long.  If the pattern is only an escape, then the
previous pattern will be used again (same as ';').
     TVX supports extensive wild card matching.  The ':M' set
parameter controls whether or not wild card matching is turned on.
Normally, it is.  The wild card matching in TVX is based on the
concept of 'sets of special characters'.  TVX predefines 6 sets of
characters, and allows the user to define one additional set.  When a
special control character is included as part of the find pattern,
then any character in the specified set will match the pattern.  The
predefined sets are:

    ^A - Alphanumeric characters: a-z, 0-9
    ^D - Digits: 0-9
    ^L - Letters: a-z
    ^O - Other characters: all characters except a-z, 0-9
    ^P - Punctuation: '.', ',', '!', '?'
    ^X - Any character: any printable character
    ^U - User character: any character in user set, set by ':U'

     Any of the sets may be specified by entering the proper control
character in the find pattern: Control-A for the ^A set.  Thus,
entering a find pattern of '^L^D' would match any letter followed by
any digit.  Since it may be desirable to match a sequence of one of
the character sets, two prefix characters are supported.  A '^W'
before one of the above sets will match a 'word' of that set.  Thus,
'^W^L' will match any word, and '^N^D' will match any number.  The
find pattern 'st^W^L' would match words starting with 'st'.  The '^N'
prefix is used to make a 'word' of characters NOT included in the
given set.  Thus, '^N^L' will match a 'word' of characters NOT


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including the letters a-z.  A match 'word' consists of any sequence of
characters (at least one character long) found in the given set, up to
the first character not in the set.  End of lines also terminate all
wild card patterns.  The only real way to adequately understand TVX
wild cards is to use them in practice.


^F- Find across buffers {<Esc>F}

     '^F' (Control-F) is the same as Find, except the search will
cross buffer boundaries.  Whenever a buffer is searched without
finding the pattern, the next buffer will be read in.  The screen will
not change until the pattern is found or the file is exhausted.  If
the pattern is not found anywhere, then the entire file will have been
written out, and there will be an empty buffer.  The '^B' command may
be used at that point to get back to the beginning of the file.


G - Get saved text {<Esc>G}

     'G' is used with 'S' and '^Y' to move text around.  'G' causes
the text in the save buffer to be inserted before the current cursor
position.  The saved text remains in the save buffer.  There must be
at least one line of text in the main buffer before 'G' will get the
text from the save buffer.


^G - Get killed line (unkill) {^G}

     The '^G' (Control-G) unkill command can be used to "unkill" one
line, which will be the last line killed with '^K'.  If the last
command was 10^K (kill 10 lines), then '^G' will retrieve only the
last line killed.  The "unkilled" line will be inserted right before
the current cursor position.  It is also possible to move single lines
around the text buffer using '^K' and '^G' - but be cautious.  Any
other '^K' command will reset the last killed line.  '^G' can also be
used to retrieve the entire line involved in a "'" (single quote) or
'"' (double quote) command.


nH - Half page {<Esc>H}

     'H' is similar to the 'P' Page command.  It causes the cursor to
move down a half screenful.  This will be typically be 12 lines.  A
negative count (e.g.  -h) moves up a half screen.


nI - Insert {<Esc>I}

     'I' causes the editor leave command mode and enter insert mode.
Following the 'I', all text typed in is inserted into the file until a
terminating escape is typed.  Inserted text is echoed on the screen as
it is inserted.  If any value is supplied for n (the default no n is
not used), then only one character is inserted, and it will have the
ascii value of n. This is the method used to enter characters that
cannot normally be entered in insert mode, such as escape or


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characters not on the keyboard.  The message "### Insert Mode ###" is
displayed on the bottom line when insert mode is entered (except when
inserting on the very last line of the file).  Many versions of TVX
will change the shape of the cursor when insert mode is entered.
{Insert is useful in the modeless version of TVX for entering either
single characters (<Esc>nI), or when several control characters will
be entered (e.g., ^L).}


J - Jump back {<Esc>J}

     The 'J' command will cause a "jump" back to the line of the
previous cursor position.  Suppose the cursor was positioned somewhere
in the middle of the file.  If the 'E' end command was entered, the
cursor would move to the end of the current buffer.  If the 'J'
command was then used, the cursor would return to the original line.
It makes it convenient to flip back and forth between two points in
the file.  It is also useful if a large cursor movement command is
accidentally entered (like when you thought you were in insert mode).


nK - Kill Character forward {^K}

     The 'K' command kills or deletes characters in a forward
direction.  '1K' would delete the character the cursor is positioned
over, and '5K' would delete the next 5 characters.


n^K - Kill lines {<Esc>K}

     '^K' (Control-K) is used to kill an entire line.  n=1 kills the
current line, negative n kills previous lines, while positive n kills
following lines.


nL - Left {^L}

     'L' moves the cursor n characters to the left.


M - Memory and Status {<Esc>M}

     The 'M' command is used to display certain status information.
The name of the file currently being edited (where the output will go)
is displayed, followed by the version of TVX.  The number of free
characters currently available in the buffer is then given (this does
not include characters that are free but not compacted yet), followed
by the number of the last line of the file.  Finally, the currently
selected repeat loop buffer and maximum number of repeat buffers
allowed is shown.


nN - Note current location {^N}

     This command notes the current line location.  Values of 1 to 9
are allowed for n. After entering '3n' for example, you can then move


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around the buffer, and later use '3^n' to return to the noted
location.  This command really remembers the current line, relative to
the current buffer beginning.  Thus if you edit out lines before the
noted location, you will not return to the same line.


n^N - Go back to noted location {<Esc>N}

     This command is used to go back to a noted location.


nO - Open line for insert {^O}

     The 'O' command will cause n blank lines to be inserted, and the
cursor positioned at the beginning of the first new line.  Following
the 'O' command, insert mode is automatically entered.  The 'O'
command is a convenient method for inserting new lines.


^O - Operating System call {<Esc>O}

     Some versions of TVX (MS-DOS and Unix, for example), will allow
an operating system command to be executed from inside of the editor.
For example, it might be useful to get a directory listing.  On
MS-DOS, after entering the ^O, the normal 'dir' command is entered.
After the directory is shown by the operating system, pressing any key
will return to the edited file.
     This command has one particularly valuable application - editing
other files.  For example, you may want to add part of another file to
the file you are currently editing.  Use the '^O' command to edit the
other file, and create a temporary file with the part you want to
add.  Then you can use the '^Y' yank command to read in the file.  For
example: Use '^O' to get enter operating system command prompt.  Then
enter something like 'tvx otherfile -o=tempfile'.  You will get a new
copy of tvx with the otherfile being edited.  Edit it to get the part
you want.  When you exit that copy of tvx, the part you want to add
will be in tempfile.  You can now yank it into the current file.


nP - Page {^P}

     The 'P' commands is the same as '25D' on 24 line terminals, and
effectively causes a new screenful to be written.  It is a convenient
method for scanning through the file.  The n count argument specifies
the number of 'pages' to scroll.  Negative values for n causes reverse
scrolling.


^P - Print Screen {<Esc>P}

     If '^P' (Control-P) is entered, and a printer is on line, the
entire contents of the screen will be sent to the printer.  Several
consecutive sequences of "P^PP^P..." (or a repeat loop: "10<P^P>$$")
can be used to print longer portions of the file.  This command will
not normally work on time shared systems such as Unix.



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nR - Right {^R}

     'R' causes the cursor to move n characters to the right.  For
convenience, the space bar is equivalent to 'R'.


^R - Restore repeat buffer {<Esc>R}

     The '^R' command will save an edited repeat buffer and delete the
edited buffer from the text.  See '^E' for a complete summary of
editing repeat buffers.


nS - Save text {<Esc>S}

     Besides the normal text buffer, TVX has a separate "save"
buffer.  This buffer can be used to move blocks of text from one part
of the file to another.  A simple 'S' command will save the current
line in the save buffer, and move the cursor down one line.  On the
screen, 'S' appears to have the same behavior as 'D'.  If n is
supplied, then n lines will be saved.  'S' can also be used
sequentially.  If no other commands intervene, consecutive 'S'
commands will continue adding lines to the save buffer.  If any other
commands are entered between consecutive 'S' commands, the previous
contents of the save buffer will be lost, and replaced with the new
line.  The 'A' command can be used to append lines to the current save
buffer without losing the previous contents.
     The '/' command can be used with 'S' and 'G' to move text.  Use
'S' to save the text to be moved, immediately delete the saved text
with '/', then insert it at the new place with 'G'.  The last line of
the file is can be saved in the save buffer only once, and an error
message will be printed if you attempt to save the last line a second
time.


nT - Tidy text {^T}

     The 'T' tidy command is specifically designed to improve the
appearance of strictly text files.  When entering letters and
documents, is it usually desirable to have the lines filled to the
right margin.  However, after editing, it is common to find a jumble
of uneven, difficult to read source lines.  The 'T' tidy command will
fill source text using the same right margin currently set for
auto-wrap.
     Tidy performs essentially the same operation as a word processor
fill function.  Word are combined on one line until the auto-wrap
margin is passed.  The 'n' count refers to the total number of
resulting lines, not the number of original lines.  Specifying a large
'n' will tidy large sections of a document.  The tidy command
recognizes lines beginning with blanks, tabs, or a period and blank
lines as special.  It will not fill those lines, thus preserving
paragraphs, tables and NROFF-like dot commands.
     One interesting capability of tidy is to put one word per source
line.  Set the auto-wrap margin to 2, then use the tidy command.  The
result will put one word per line.



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^T - TERMINATE - ABORT EDIT SESSION {<Esc>T}

     The '^T' (Control-T) command aborts directly to the operating
system.  The original file is left untouched, and no backup file is
created.  This is a fairly dangerous command in that all editing
performed will be lost (unless the '^B' file beginning command was
used).  You will be asked to confirm the '^T' command with a Y or N.
If the '^T' is performed accidentally, the backup log file can be
applied to the current version of the file after the '^T' has been
edited out of the log file (no backup file will have been created
after the '^T').  The '^T' command is most useful when you decide you
don't want to make any changes and want to exit from TVX quickly.
Exiting with the '^T' command is similar to using the 'R' read only
switch at the beginning.
     If you have used the '^B' command, a work file copy of the
original will have been written out containing all the edits performed
before the '^B'.  When you use '^T' and this work file has been saved,
a message informing you of its existence will be printed.  You can
then either use that file, or delete it at the operating system
level.


nU - Up {^U}

     The 'U' command moves the cursor up n lines, positioning the
cursor at the beginning of the line.


n^U - Up in column {<Esc>U}

     The '^U' (Control-U) is the opposite of '^D', and moves the
cursor up in column.


nV - Verify the screen {^V}

     In regular screen editing mode, the 'V' command causes the screen
to be rewritten.  This is sometimes necessary to get a true version of
the screen after error messages have been written or when editing
lines longer than 80 columns.  On terminals without reverse screen
scroll, the 'V' command forces the cursor to the home display line
(usually line 16).  In screen mode, 'V' ignores any n.
     In tty mode, the 'V' command is used to type lines from the file
on the terminal.  A negative n will type out lines preceding the
current line.  An n of 1 types the current line, with the current
cursor position indicated by '/'.  An n greater than 1 types the
current line, plus the following n-1 lines.  A command '-12v12v' would
type 24 lines on the terminal: 12 before, the current line, and 11
following.


n^W - Write out buffer, read next one {<Esc>W}

     The '^W' (Control-W) command is used to explicitly go from one
buffer to the next.  By default, when n is >= 0, the entire current
buffer is written to the new version of the file being edited, and the


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next buffer full of the original file (if any) is read in.  If a
negative n is supplied (any negative value, most easily -^W), then
only the part of the buffer up to (but not including) the current line
is written.  Then as much more of the file as possible is read to the
end of the current buffer.  Thus, a negative n is useful when a file
won't fit, and the split point is at an awkward place.  It is also
useful when a '^Y' yanked file won't fit.


^X - eXit {<Esc>X}

     '^X' (Control-X) causes the remainder of the file to be written
out, and the editor exited.  The entire file will be written, no
matter where the cursor happens to be positioned when the '^X' command
is entered.  This is the normal conclusion of an editing session.  All
work files are deleted, the original file renamed to the back up file,
and the newly edited file renamed to the original name.  See the
appendix on tvx file handling conventions for more details.


n^Y - Yank text to/from external file (file merge) {<Esc>Y}

     A '^Y' (Control-Y) with a positive n is similar to 'S' save, but
the text saved in the save buffer is read in from an external file
instead of from the current buffer.  When '^Y' is entered, the save
buffer is cleared, the buffer compactor invoked, and then the user is
prompted for the name of the file to read.  TVX then will read as much
of the external file into the save buffer as it can.  The 'G' command
can then be used to insert the save buffer text into the current file
at the desired location.  If there is not enough room in the save
buffer to hold the entire file, then only part of the file is read and
a diagnostic message printed.  The '-S' switch can be used when TVX is
first invoked to reserve a large save buffer for merging larger
files.  You can also use the '-^W' command to write out the front part
of the file, and then 'G' to get the saved file.  (Note: '^Y' may not
be used from within a log command file.  See section on backup log
file.)
     A negative n (e.g., '-^Y') can also be used with the yank
command.  If the n is negative, then the contents of the save buffer
will be written to a new file.  After '-^Y' is entered, you will be
prompted for the name of the output file, and then the contents of the
save buffer will be written to that file.


nBACKSPACE - Delete previous character {BS}

     The BACKSPACE key will delete the previous character on the
screen.  It is also used for editing input keystrokes for Insert,
Find, and repeat loops.


n; - Find again

     The ';' (semicolon) command causes the previous pattern to be
searched for again.  This is more convenient that entering 'F$'
again.  The 'n' has the same meaning, positive searches forwards,


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negative backwards.


/ - delete last thing {<Esc>/}

     The '/' (slash) command is useful when used with 'F' (find), 'S'
(save), 'G' (get), 'TAB' (word right), and '{' (word left).  It causes
the last pattern used to be deleted.  Thus "Fxxx$/Iyyzz$" will delete
the pattern 'xxx' and insert 'yyzz'.  When used after an 'S', it
causes the just saved lines to be deleted from the text buffer (but
not the save buffer).  After the G, it causes the text just inserted
from the save buffer to be deleted from the text buffer.  After a
'TAB' or '{', '/' will delete the word or words just skipped over.
Slash must be used immediately following an 'S', 'G', 'TAB', '{', 'F',
'^F', or ';' command.  This command knows how to take wild card
matches into account.


= - delete last thing and enter insert mode {<Esc>=}

     The '=' (equals) command is the same as the '/' command, except
insert mode is automatically entered, thus achieving the effect of
'/I' command sequence.


' - Delete previous part of line (single quote) {<Esc>'}

     The "'" command will delete all the characters in the current
line before the cursor.


" - Delete rest of line (double quote) {<Esc>"}

     The '"' command will delete from the cursor forward to the end of
the line.  The "end of line" mark will remain.  Note that the single
quote has one tick, representing the "first" part of the line, while
the double quote has two ticks, representing the "second" part of the
line.


, - beginning of line (comma) {<Esc>,}

     The ',' command will move the cursor to the beginning of the
current line.


. - end of line (period) {<Esc>.}

     The '.' command will move the cursor to the end of the current
line.








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* - Insert last pattern found {<Esc>*}

     The last pattern found with the find command (up to 100
characters) is saved in an internal buffer.  The '*' command will
insert that pattern into the text at the current cursor location.  If
the last find pattern included wild card characters, the pattern saved
will be the actual text matched, and not the wild cards themselves.
You must be back in command mode to use this command.


nTAB, n{ - Skip over words {<Esc>^I, <Esc>{}

     The 'TAB' (TAB key, CTRL-I) and '{' commands skip over words.  A
word is any contiguous set of alphabetic characters (a-z) or digits
(0-9).  'TAB' moves forwards, while '{' moves backwards.  The 'n'
count may be used to skip over several words at once, and a negative
count reverses the direction of the move.  A value of 0 for n will
move the cursor to the beginning of the current word rather than the
previous word as -{ would.  Note that '{' is usually aliased to '['
since these are often reversed case on different terminals.


n< - begin repeat loop {<Esc><}

     TVX has up to 9 different repeat loop buffers which allow an
arbitrary sequence of commands to be repeatedly executed.  When n< is
typed, the editor echoes 'Repeat: n<' at the bottom of the screen.
The user then types in any series of commands to be repeated n times.
The repeat command is terminated with a matching '>' and a double
escape (echoed as $$).  Repeat loops may not be nested.  The repeat
loop has two typical useful functions: one is to replace multiple
occurrences of a string with another (e.g., "10<fone$=two$>$$"), a
second is to save a complicated sequence of commands to be repeated as
necessary with the '&' command (i.e., a macro facility).  Each repeat
loop may have up to 100 characters.
     When a repeat loop is entered from the keyboard, it is saved in
one of up to 9 repeat loop buffers, each identified by an integer
value.  The repeat buffer which is currently in use can be set with
the 'n:R' command.  Buffer 1 will be used by default.  The number of
repeat buffers available and the currently active one can be
determined by using the 'M' command.  The availability of repeat
buffers allows the definition of 'edit macros'.  Commonly used
sequences of editor commands can be saved in a given repeat buffer,
then selected with 'n:R' and executed with the '&' command.
     For example, "3:R<fpat1$>$$" would select repeat buffer 3 and
enter the repeat command into it (and execute the command once).
Other "macros" could be entered in other buffers, and then the given
example used again by "3:R&".  A count 'n' of 0 can be used to enter a
macro without executing it.  The indirect command file facility ('@'
command) can also be used to define and load commonly used macros.
The results of using one repeat buffer from within another is not
guaranteed, and should be tried only at your own risk.
     The '#' command has been provided to simplify the above
sequence.  Entering '23#4' for example, is exactly the same as
entering '4:r23&'.  The n value is a count, and the single digit after
the '#' is the repeat buffer to use.


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>$$ - End of repeat loop {>$$}

     The repeat loop is terminated by a '>' and a double escape.
Note: '$$' represents escape.


n& - execute repeat loop {<Esc>&}

     The '&' command executes the commands in the currently selected
repeat buffer n times.


n#k - execute repeat loop k {<Esc>#}

     This command is an easy to execute a specified repeat buffer.
The n is a count and the k is a single digit repeat buffer number.
This command is exactly equivalent to 'k:rn&'.  Repeat buffer k
becomes the current buffer after '#' is executed.


n~ - change case {<Esc>~}

     This command chanages the case of the character under the
cursor.


? - Help {<Esc>?}

     The '?' command causes help screens to be displayed.  There are
two help screens.  The first includes a summary of transitory values:
a summary of settable ':' parameters, the contents of the repeat and
find buffers, as well as buffer space left.  On 16 bit processors, if
the space left is greater than 32,000 characters, then 30,000+x will
be shown, where the total is 30,000 plus x. The first screen also
shows the last 16 commands you have entered.  This may be useful if
you entered "commands" while you thought you were in insert mode to
see what your keystrokes might have done.  The second screen of help
summarizes the command set.


@ - Invoke command file {<Esc>@}

     Causes a prompt for command file name.  Commands in that file are
then read in and executed.  See description of backup command files
below for details.  This command is most useful for loading repeat
macros.


n:P - Set special parameters {<Esc>:}

     The ':' (colon) command is used to set several TVX
characteristics.  The value n entered before the ':' is the value to
set the parameter to, and the character P that follows the ':' defines
the parameter to set.  Valid parameters include:

n:A - set autoindent.  A value of 1 turns on autoindent, 0 off.


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   Autoindent is useful for programmers.  When autoindent is on, each
   new line started while in insert mode will be indented to the same
   leading tab/blank space as the previous line.  Use blanks or tabs
   to add indentation, and backspace to backup over indentation.

n:C - set cut mode.  When cut mode is enabled (1), killed lines are
   also saved in the save buffer.  This works for individual kill
   commands, e.g.  'kkk' will save only the line associated with the
   3rd k, while '3k' will save 3 lines in the save buffer.  With cut
   mode off, kill line does not save the lines in the save buffer.

n:D - set home "display" line to n. The display line is the line the
   cursor homes to after a verify command.  (Default home display
   line: 16 on 24 line terminals, 9 on 16 line terminals.)

n:E - Expand tab value.  The default value for ':E' is 8, which causes
   the tab character (^I) to be expanded to multiples of 8 columns.
   This is the standard used on most systems.  Setting ':E' to 0 will
   cause tabs to be displayed as '^I' instead.  Other values are
   possible, but less useful.

n:F - Find case mode: n <= 0 sets find mode to search for exact case
   of pattern, n > 0 (default) set search mode to ignore upper/lower
   case.

n:M - Match wild cards.  (default=1).  If on, then matching of the TVX
   wild card sets is enabled.  If off, then the wild card control
   characters will match the actual control characters in the file.

:o - set output file name.  When ':o' is entered, you will be prompted
   for the name of the edited output file.  This overrides the '-o'
   command line switch, and can be used to change your mind about the
   name of the edited file.  If the output file name is different than
   the input file name, the input file will not be renamed to the
   backup file name.

n:R - select repeat buffer n. (default=1).  Repeat buffer n becomes
   the current repeat buffer executed with the '&' command.  The 'm'
   status command will show how many repeat buffers are available for
   a given implementation.

n:S - scroll lines: This parameter sets how many lines the cursor will
   move before the screen scrolls.  The exact effect of the scroll
   parameter depends on the terminal characteristics.  On terminals
   that allow a blank line to be inserted at the top, ':S' sets how
   many lines cursor will move above and below home display line
   before scrolling.  Default is 0. Changing the scroll value to 4
   would let the cursor move up and down 4 lines from the home display
   line before actually scrolling the screen.  Some users might find
   this update mode more pleasant to use.  This will be almost
   essential on heavily loaded time shared systems.  For terminals
   that do not allow a blank line to be inserted at the top (no
   reverse scroll), 'n:S' sets how many lines cursor will move above
   the home display line before the screen is rewritten.  Default is
   14, which causes the cursor to move nearly all the way to the top
   before rewriting the screen.


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n:T - tty mode.  A 0 is screen mode, a 1 is tty mode.

:U - set User Wild Cards.  After entering :U, you will be prompted for
   a user wild card set.  You can use backspace to correct your entry,
   and '<Esc><Backspace>' to enter backspace and '<Esc><Esc>' to enter
   escape.

n:V - virtual window lines.  The 'n:V' will set the virtual window to
   n lines.  N must be between 3 and the number of hardware lines on
   the terminal.  A smaller virtual window is extremely useful on busy
   time shared systems, or when TVX is used over a telephone line at a
   relatively slow baud rate.  Typically, a virtual window of 7 or 9
   is big enough to show a reasonable part of the file, yet small
   enough to reduce the overhead of screen update at slow speeds.  A
   window of 3 or 5 can even be used if needed.  Note that the virtual
   window can be set at start up time by using the '-#' switch.  The
   virtual window will use the top n physical lines of the display.
   Error messages and prompts will still be displayed on the bottom
   physical line.  Scanning up with 'u' will cause the lines to be
   scrolled onto the unused part of the screen, and gives a true
   picture of the file showing more lines than the window size.

n:W - set auto wrap width.  The ':W' parameter sets the column number
   used for auto wrap mode.  When the auto wrap is set to a value
   greater that 1, TVX will automatically insert an end of line when
   the user types the first blank after the given column.  Normally,
   the user must manually hit the RETURN key to force an end of line.
   The auto wrap mode allows continuous entry of text without worrying
   about the right margin.  A good value to use for ':W' is 10 columns
   less than the screen width (70 on 80 columns screens).

An invalid parameter value or name causes an error message.


























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                   *** BACKUP LOG FILE FEATURE ***

     TVX has a backup log file feature.  When the feature is enabled,
all commands entered in any given session are saved on a file called
"BACKUP.LOG" on the current directory or drive.  If for some reason
you destroy your file during an editing session (like accidentally
entering "100^K" instead of "100K"), you won't have to manually
re-edit the backup version of the file.  (By default, the log file is
disabled.  The 'L' invocation time switch will respectively disable or
enable the log file feature.)

     The "BACKUP.LOG" file contains all the commands you entered in
the last session.  Most commands will appear in the log file as you
entered them: R, U, D, etc.  However, all control characters,
backspace, and the atsign are encoded in the log file to make them
appear as printable characters.  The atsign '@' is used as an encoding
character.  So, for example, tabs appear as '@I', escapes as '@[',
RETURNs as '@M', and so on.  Control-A would appear as '@A'.  The '@'
itself would appear as '@@'.  Backspace appears as '@H'.  These escape
sequences may be split across the end of a line in the log file.  The
end of line marks in the log file are not part of the command stream
and are ignored.

     The procedure for using the "BACKUP.LOG" file to restore your
file is as follows.  When you realize you have made a mistake, enter
the '^X' exit command.  Copy "BACKUP.LOG" to a temporary working
file.  Now edit that temporary version of the log file to remove the
mistakes, which should be near the end of the file.

     Once the log file has been edited to remove the bad commands, you
should then re-edit the original file (the one without the mistakes).
The latest version of the file will be the one with the mistakes, and
should usually be killed.  Start TVX and read in the file.  Then enter
the '@' command and supply the name of the "repaired" log file.  All
the commands in that log file will be applied to the original file.
You should be careful to start the '@' command when the cursor is at a
specific place such as the beginning of the file.  After the '@'
command is finished, your file will be in the same shape it was before
the mistake.

     For example, suppose you are editing a file called "MYFILE0.TXT"
and that you accidentally kill 100 lines.  When you realize your
mistake, you enter '^X' to exit.  Then you should copy or rename the
BACKUP.LOG file to a new temporary file - say FIX.LOG.  The current
version of the file you were editing is the bad file and should be
deleted.  On CP/M and MS-DOS versions, you would rename MYFILE0.BAK to
be MYFILE0.TXT again.  Then, edit FIX.LOG to remove the command that
killed 100 lines and the quit command ("100@K@X").  Exit again, and
re-edit MYFILE0.TXT.  If you then enter the '@' command, and respond
with FIX.LOG as the name of the command file, your file will be
brought back to the state it was in right before the '100^K'.

     There are some special cases that require special attention when
using the backup log file.  These cases involve the entry of file
names or strings, such as for '^Y', ':o', and ':u'.  For 'Y', the file
read as a part of the given command is read using the same I/O channel


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as the backup log file input, and thus both cannot be used at the same
time.  If the backup log file contains any '^Y' commands (displayed in
the log file as '@Y'), you must remove them.  Obviously, this will
alter the order of the commands in the file, and you will need to use
a special procedure.  Suppose, for example, that the backup log file
contained one '^Y' command.  Make two copies of the backup log file.
Edit the first, and remove all commands following the '^Y' command,
including the '^Y' command.  Then edit the other copy, and remove all
commands before the '^Y', including the '^Y'.  Then, edit the backup
copy of the original file.  First, apply the first backup log file.
This will get you to the point right before the '^Y'.  Then without
changing the cursor position, manually enter the '^Y' command and file
name.  Finally, apply the second copy of the backup log file.

     For ':o' and ':u', the filename or user set are not save as part
of the log file, and you will in fact be prompted for the file name or
user set while the log file is being executed.  There is no real clean
way around this.

     It is also possible to write log command files of your own to
carry out specific commands.  This allows the creation of "macros"
that can be executed as needed.  When creating log files of your own,
you should remember that control characters and backspaces must appear
as encoded characters.  The '@' is the encoding character.  Control
characters will appear as '@' followed by the appropriate letter: '^I'
= '@I', enter = '@M', etc.  An '@' itself is '@@', and backspace is
'@H', although you should never need a backspace in your own files
(use -K).






























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