The C Users' Group Library 1994 August/wc-cdrom-cusersgrouplibrary-1994-08.iso/vol_100/179_01/tvx_refa.doc

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                         TVX Reference Manual



     This is  the  Reference  Manual  for  TVX, a public domain 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).   Any
comments,  bug reports, or suggestions should be sent to that address.
This manual contains the formal descriptions for each editor  command.
An  appendix  gives  some notes for installing TVX on various systems.
The name TVX is derived from "TV" editor for any terminal ("X").



*** GETTING STARTED ***

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

          tvx filename -switch1 -switch2 ...

     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 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 A:CONFIG.TVX on  CP/M  and  for
          /bin/CONFIG.TVX  on  MS-DOS.  The -c switch is not supported
          on all implementations.
     -[no]b -- generate a .BAK version  of  the  original  (the  usual
          default).   The -nob option means no .BAK file is generated.
          This 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.


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          See the special appendix on tty mode.
     -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.  On MS-DOS, TVX can also be used to
edit  standard BASIC programs.  BASIC programs must be saved using the
",A" switch from Microsoft BASIC.  When editing BASIC files, care must
be taken to preserve the BASIC statement line numbers.  On  CP/M,  TVX
can  be  used  as  a totally compatible alternative to ED.  Because of
memory limitations, the CP/M version contains a subset of the commands
available on the regular version.


*** General Comments ***

     TVX functions almost identically for all versions.  All  commands
are  normally  the  same,  although  it  is  possible to create custom
versions with a different 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  keys  is  the  one  normally used by the respective
operating systems.  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
input text.  When TVX is accepting commands, BACKSPACE will cause  the
character immediately before the cursor to be deleted.

     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 CP/M version of TVX allows slightly over
20,000 characters in the buffer (950 lines).  The MS-DOS versions will
allow up to almost 64K 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


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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.

     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.   Note that on terminals that cannot disable auto wrap around
for column 80, when you are making changes to a line  that  is  longer
that 80 columns, the line will wrap around to the next display line so
that the entire line is visible.  The wrap will disappear when you use
the  'd'  or 'u' commands, or rewrite the screen with the 'v' command.
Most versions will not wrap long lines.

     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 character between command and
insert mode.

     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  CP/M  and  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.










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                   *** Summary of TVX Commands ***


     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

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


^B - Beginning of file

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


nC - Change

     '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' 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.




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n^D - Down in column

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


n^E - Edit repeat buffer n

     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  give  a
value  0 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
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' 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


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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
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

     '^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.




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G - Get saved text

     '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)

     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

     '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

     '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  other  than  the  default  value  1  is
supplied  for n, 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
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.


J - Jump back

     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).




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nK - Kill Character forward

     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

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


M - Memory and Status

     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

     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
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

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


nO - Open line for insert

     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.






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^O - Operating System call

     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

     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

     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.


nR - Right

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


^R - Restore repeat buffer

     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

     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


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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

     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.


^T - TERMINATE - ABORT EDIT SESSION

     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,


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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

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


n^U - Up in column

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


nV - Verify the screen

     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

     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
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

     '^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


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appendix on tvx file handling conventions for more details.


n^Y - Yank text to/from external file (file merge)

     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

     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,
negative backwards.


/ - delete last thing

     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.



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= - delete last thing and enter insert mode

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


' - Delete previous part of line (single quote)

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


" - Delete rest of line (double quote)

     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)

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


. - end of line (period)

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


* - Insert last pattern found

     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

     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.  Note that  '{'  is  usually
aliased  to  '['  since  these  are  often  reversed case on different
terminals.





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n< - begin repeat loop

     TVX has three  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 three 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 three 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.


>$$ - End of repeat loop

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


n& - execute repeat loop

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


n#k - execute repeat loop k

     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.




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? - Help

     The '?'  command  causes help screens do 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 or 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

     Causes prompt  for  command file name.  Commands in that file are
then read in and executed.  See description of  backup  command  files
below for details.


n:P - Set special parameters

     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.
   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: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


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   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.

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

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 currently logged drive on  CP/M  and  the  current
directory  on MS-DOS and Unix systems.  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 'B' invocation time switch will respectively disable or enable the
log file feature.)

     The "BACKUP.LOG"  (the  CP/M  convention  will  be  used  in this
description) 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 two cases that require special attention when using the
backup  log  file.  If you used a '^B' command during the session with


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S