Simtel MSDOS 1992 June/SIMTEL_0692.cdr/msdos/keyboard/cedwars2.arc/CED.ART

Text File | 1987-11-15 | 16.7 KB | 387 lines

Living With DOS:  CED, the Command Editor
by Barry Simon

Copyright (c) 1986, Capital PC User Group Inc.
This material may be republished only for internal use
by other not-for-profit user groups.

Posted on Compuserve with permission of CPCUG.  May not be
reproduced without including the above copyright notice.

Published in the January 1986 issue of the Capital PC Monitor.


This article is the second in a series that discusses products
and utilities that enhance the usefulness and ease of use of
DOS, the Disk Operating System.  This article discusses a
program called CED (for Command EDitor) by Chris Dunford.  CED
remains loaded in  memory and available while you are in DOS and
in some additional programs like EDLIN and DEBUG; it sits
between the commands you type in and DOS.

CED is the kind of program that you can't do without once you
start using it.  Indeed, if I were travelling somewhere and were
told that I'd have a PC with only the basic application
software, the first utility I would be sure to bring along would
be CED.

CED was originally placed in the public domain by its author.
An enhanced version, PROFESSIONAL CED, was recently introduced
as a commercial product.  This review discusses the public
domain version of CED, version 1.0D; some of the enhanced
features of the commercial version will be described in a
separate article that will appear in a future issue of the
MONITOR.


OVERVIEW

CED provides four major facilities:

  1.  command editing
  2.  a command stack or buffer
  3.  recalling a program with the same parameters
  4.  synonyms

Imagine exiting your word processor after working on a letter or
document.  You enter a command in DOS, perhaps copying a file to
the directory where you have your spelling checker, a directory
with a long path name.  Before hitting <enter>, you scan the
command and discover a typing error in the middle.
Unfortunately, DOS does not have a full-function command editor
so you cannot go back and edit the command as you can with a
word processor; instead, you have to retype the correct command.
CED resolves this problem by providing a command editing
capability for DOS.

And, having learned to use the DOS editing keys (F1, F3) to
avoid having to retype the last command, haven't you wished that
you had the capability to recall the command that was made the
one before the last one or even six commands ago?  That's what
the command stack is all about.

And having used your word processing program to edit a file
"therise.and", haven't you wished that you could call up the
program on this last used file without having to remember the
precise file name.  That's what parameter recall is all about.

And aren't there some long commands that you're tired of typing
and you wish you could abbreviate them or use shorthand
notations for them?  That's what the synonyms are all about --
creating macros as shorthand methods for issuing a set of
commands.


The Command Line Editor

The command editor provides most of the features that you would
want and expect in editing the current line.  You can move the
cursor non-destructively with the <left-> and <right-arrow> keys
and use the <delete> key to delete the character at the cursor.
In the default mode, striking a key overwrites the character at
the cursor, i.e., replaces the character at the cursor with the
character that was struck.  The <insert> key toggles between
this mode and an insert mode where the key struck is inserted
just before the cursor.  The <home> and <end> keys take the
cursor to the beginning and end of the line respectively.
<Ctrl-End> erases from the cursor to the end of the line; <Ctrl-
left-> and <Ctrl-right-arrow> move the cursor a word at a time.

The editing keys are helpful in normal use but are especially
useful because you can recall previous commands from a stack and
edit them.  For example, PC-WRITE has an editing program called
ed.exe and a printing program called pr.exe.  After exiting the
editor which you called up with ed FILENAME, you need only
recall this command from the stack, hit <home>, then "pr" and
finally <enter> to issue the command pr FILENAME.


The Command Stack

The <left-> and <right-arrow> keys move the cursor in the
obvious manner.  It would be useful to have full-screen editing
in DOS so that one could use the up and down cursor to move
around the screen reissuing commands.  In many ways, the command
stack does precisely that; however, it also allows you to use
commands that have scrolled off the screen!

When CED is invoked, it reserves 2K of memory (this number can
be modified) to store the last 2,000 characters sent as commands
to DOS.  After issuing a new command, the <up-arrow> key
restores that command to the command line.  If you just <enter>
without any editing of the command line, you move one position
down in the stack; that is, the <up-arrow> key recalls the
command just issued and the <down-arrow> key recalls the next
command in the stack.  This is especially convenient for
recycling a series of commands.

If you should change your mind while you're in the stack, you
can press the <esc> key to blank the command line.

The stack idea is enhanced with many thoughtful extras which are
typical of the CED program.  One is the "ignore character".  The
ignore character tells CED not to include in the stack the
command that follows.  The default value for the ignore
character is <Ctrl-N> or ^N (* in PROFESSIONAL CED) but that can
be changed by the user.  If, for example, you enter "dir" at the
command line, the command is added to the stack.  However, by
entering "^Ndir", the command is issued to DOS but is not placed
in the stack.

This is especially useful for key redefinitions.  I have defined
<F1> to mean "dir^" (where ^ means <enter>).  Because I can get
that command by hitting <F1>, there is no reason to stack it, so
<F1> is really defined to CED as "^Ndir^".  In general, you
should only do this with redefinitions that end in <enter>.  For
example, my <Alt-F1> key means "dir[]" where [] means space.
Since I would want to recall a command such as "dir
C:\bin\dump\vdump\ce*.*", I do not put a ^N before that dir.

Another use for the ignore character is to stack synonyms.  As
I'll explain shortly, you can set up lists of short names for
commands or sets of commands that you use often.  If there are
sets of commands, both the synonym and the individual commands
get stacked; depending upon the size of your commands, this
could fill up the stack.  Thus, you would want to include the
ignore character before the individual commands in your synonym
definitions.  [This is not necessary in PROFESSIONAL CED because
the commands within synonyms are NOT stacked.]  WARNING: Because
of the way CED processes the ignore character, you should not
include it in front of the first command in a multiple command
synonym nor in front of a command which is a synonym if you have
nested synonyms.


Parameter Recall

One can tell CED that one wishes to have certain programs
normally called up with the same parameters that were used the
last time the program was loaded during the current seesion.
Thus, if your word processor is called ed.exe and you issue the
command

  ced pcall ed

then this feature is made available for the command "ed".  If
you enter the command "ed oldfile newfile", CED stores the
"oldfile newfile".  The next time you type "ed" followed by
<Enter>, CED will resupply these parameters by flashing them on
the screen and passing them to the ed-program.  If you want to
apply ed to another file, typing "ed newerfile" does precisely
what you want and stores "newerfile" in the pcall buffer.  If
you want to invoke ed without any parameters, typing "ed " (note
the space) followed by <Enter> will work.  The pcalled command
can be a CED synonym.


Loading CED and Issuing Commands to It

The final feature of CED is its "synonyms".  Before explaining
this, it is first necessary to explain how you issue commands to
CED.  There are two ways.

First, you can enter CED commands on the DOS command line.  For
example, if CED has not been loaded before, entering "ced ic !"
from the command line will load CED and change the ignore
character (ic) to !.  The second way is to place any number of
CED commands in a "configuration file" and enter the command
"ced -fPATH\FILENAME", where PATH is the complete DOS path list
and FILENAME is the name of your configuration file that
contains the CED commands.  Thus, I load CED by including the
following line in my autoexec.bat file

  ced -b2048,128,6144,256,256,128 -fC:\bin\lists\cedfile

(The -b part of the command sets the sizes for the various CED
buffers to values different from their defaults.  Even with my
large 6K buffer for synonyms, CED takes only 17K of memory.)

Some warnings are in order here:  Entering a command beginning
with "ced" from DOS will not reload CED but, if issued in a
BATch file, such a command will reload CED from scratch.
Therefore, you should make sure that the initial loading of CED
is in a BATch file.  A second point is that commands in a CED
configuration file must not begin with "ced".  A third point is
that one cannot call up synonyms from a BATch file.  (These
restrictions do not apply to PROFESSIONAL CED.)

This dual method of setting synonyms is useful, especially since
you can define a synonym more than once -- the last definition
is the one that counts.  For example, when I want to try out a
new and complicated definition, say to make "foo" mean COMMAND
STRING, I type in "ced syn foo COMMAND STRING" at the DOS
command line and then check that "foo" does what I want.  If it
doesn't, I use CED to recall this command and edit the COMMAND
STRING.  Once I get it right, I add the command to my CED
configuration file.


Synonyms

In its simplest form, a synonym allows you to replace a command
with a shorter (or easier to remember) alternate name.  Thus,
for example, you can make "d" a synonym for "dir" by issuing the
command

  ced syn d dir

at the command line or by including the following line in your
CED configuration file

  syn d dir

Once that is done, you can type "d" and the command "dir" is
issued.

You may be concerned that calling up your favorite program,
doodle, might be interpreted by the CED-enhanced DOS as
diroodle, but CED is smarter than that; unless the synonym is
the only thing on the line or is followed by a space, it is not
treated as a synonym.  Moreover, if you type " d" (note the
leading space), the synonym processing does not take place and a
DOS error message is issued.

Like BATch files, synonyms also allow parameters.  Thus, if you
type

  ced syn wd dir %1/w

at the command line, the command "wd \bin\batfiles" is
interpreted by DOS as "wd dir \bin\batfiles/w" and produces a
wide listing of the specified directory.

The above remark about "diroodle" illustrates a major difference
between synonyms and keyboard enhancer products such as
SUPERKEY, PROKEY, or ANSI.SYS.  If you used a keyboard enhancer
to redefine "d" to mean "dir", then "doodle" would be sent to
DOS as "diroodirle".  While synonyms can be assigned to any key
or key combinations, you will want to limit a keyboard enhancer
to Function Keys, <alt> and <ctrl> keys, which may be harder to
remember and more awkward to strike.

One of the more powerful features of the synonym is the ability
to issue several commands with one synonym.  While the default
"chain character" is ^, I have used CED to change the chain
character to & for clarity.  Here is an involved example, that I
actually use, to demonstrate chaining multiple commands:

  syn ed key pcw/ml /op35&^Nmenu C:\words\pcwrite\m_pcwrit &^Ned@
  %1&^Nkey /mc /op00&^Ncls

Using the above example, CED parses this single synonym into its
five separate component commands:

  key pcw/ml /op35
  menu C:\words\pcwrite\m_pcwrit
  ed@ %1
  key /mc /op00
  cls

If I issue the command "ed my.ltr" to DOS, the following
happens.  The first command loads the appropriate SUPERKEY
macros; the second loads the file required to make my mouse work
properly in my word processor; and the third command calls up my
word processor by issuing the command "ed@ my.ltr".  The last
two commands are not executed until I have completed my word
processing.  When I exit my word processor, the fourth command
is issued to clear my SUPERKEY macros.  The last command clears
the screen.

When I want to run a program in a special directory, I include
"cd\directory name" as one of the commands in the synonym and
get a synonym similar to what are sometimes called gobatfiles.


Synonyms vs. BATch Files

You may get the idea that a synonym is similar to a small BATch
file and you're right about that.  So why not use BATch files?

In general, the storage space requirements and execution speeds
for both synonyms and BATch files are nearly identical on a hard
disk while synonyms are much faster on a floppy based system.
For me, however, the deciding factor is convenience.  With
synonyms, you can try one out by simply typing it on one line; to
change or edit it, you recall that line from the stack and modify
it.  With BATch files, you must load an editor, enter or modify
the file, exit the edit, and then test the file.

Another convenience with synonyms is that all your short "batch
files" are in one place.  When I had to transfer my files from a
two hard disk system at the office to a one hard disk system at
home, I merely had to do a single global search and replace from
D: to C: within my CED configuration file rather than edit many
individual files.  Using synonyms also allows me to order them
any way I want in the file and thus keep track of them in a
manner that wouldn't be possible with individual BATch files.

So why use BATch files at all?  Well, first, there is a
limitation on how long synonyms can be (255 characters; 127 if
the synonym is being typed in at the DOS command line rather
than placed in a configuration file by your word processor or
editor).  By nesting or chaining synonyms, one can often
overcome this restriction.  Secondly, there are times when you
would want to use the features of "echo off" to leave nothing on
the screen.  Finally, there are various enhancements for BATch
files available like Extended Batch Language (EBL) which make
them useful in special situations where synonyms won't work.

If you've discovered the capability of BATch files to perform
lots of little tasks, I can assure you that not long after you
install CED, you'll be adding new synonyms to your configuration
file and erasing old BATch files from your hard disk.


Some Examples of Synonynms

For my purposes, the most common use for synonyms is the "gt
synonym"; gt is an abbreviation for "go to".  For each
subdirectory, I have one or more gt synonyms.  For example, both
gtbatfiles and gtbat are synonyms for

  C:&^Ncd\bin\batfiles

Thus I need not remember the precise path or even name of my
various directories and travelling around my hard disk is
virtually effortless.  Of course some discipline is required to
keep this list current so I have a synonym called makedir which
not only makes a directory but calls up my editor acting on my
CED configuration file to add the necessary gt synonyms.

Another invaluable use for synonyms is for executing programs
that you always invoke with the same parameters.  For example,
because I always call up FILE COMMAND II as "fc2/q", I use the
synonym "syn fc fc2/q".  This saves me from having to remember
the proper parameter necessary for execution.

Other useful synonyms involve control of your printer.  Make a
file, say "send.tf", with only a Ctrl-L in it.  Put this file in
the directory whose path name is "george" and make a synonym:

  syn tf copy "george"\send.tf prn

Then typing "tf" will send a top-of-page command to your
printer.  I use several synonyms in this way, including one that
I call "boldprn" that turns boldface print on and off.

You can also use synonyms to catch your typing mistakes.  For
example, if you find that you often type "dit" rather than
"dir"; then make "syn dit dir" a line in your CED configuration
file.

A final use of synonyms that I should mention is to allow one to
shorten one's DOS search path.  I once had C:\bin\private\norton
in my path but now have synnoyms like "syn nu
C:\bin\private\norton\nu" in my CED configuration file.


SUMMARY

CED is a program that really fits the cliche that "once you use
it, you don't know how you ever did without it".  If I had a
penny for every keystroke it saved me over the past six months,
I'd be a rich man.

CED, version 1.0D, is available on Compuserve.
See the file PCED.ART for a discussion of PCED.