------------------------------------------------------------
DIET.DOC for DIET.EXE v.1.45F
------ by Teddy Matsumoto ---------
(DOCFILE: October 1992)
------------------------------------------------------------


1.0. OVERVIEW.

1.1. DIET.EXE reduces the disk-storage space needed by ex-
ecutable and data files WITHOUT giving up immediate access to
such files. DIET is a Freeware Program.

(a) When DIET compresses an EXECUTABLE file (.EXE or .COM),
it adds a header that automatically expands the file when
it is executed.

(b) On average, DIET reduces the size of .EXE & .COM files
by 40%.

(c) Self-expansion of DIETed .EXE & .COM files is so fast
that it is difficult to measure the change in the speed
of file execution. You certainly won't notice any
change.

(d) DIET's self-expansion of .EXE and .COM files is similar
to PKLITE or LZEXE, except that DIET also lets you com-
press overlay files -- something that PKLITE and LZEXE
cannot do.


1.2. What makes DIET really unique is its ability to compress
DATA Files and to automatically expand them when you call them
into an Word Processor or Editor to read or change them.

(a) To use that feature, you must load DIET so that it is
resident in memory (i.e., Terminate and Stay Resident, or
TSR).

(b) DIET reduces the size of an average DATA File by 2/3rd.

(c) DIET's automatic expansion of Data Files adds a little
time (on a 386SX-16 system, about 3 sec. compared to
loading a 100k byte unDIETed text file into an editor).
But that is a small price for the benefit of being able
to keep infrequently-used Data Files on your Hard Disk,
instead of having to store them on floppies. And you can
optionally set up DIET so that it will automatically
recompress Data Files when you exit your Editor.

(d) Many -- but not all -- application programs can use
DIETed DATA files. For example, QUATTRO can use DIETed
???.WQ1 files; dBASE cannot use DIETed ???.DBF files.
You'll have to experiment.

















































This document is the USER'S GUIDE for DIET v.1.45F. To learn
about DIET's internals and changes from version to version, see
DIETAPI.DOC and DIETTECH.DOC Those much more technical documents
are of no importance to the average USER of DIET, but are avail-
able for programmers and the curious.



2.0. A QUICK INTRODUCTION TO WHAT DIET CAN DO.


2.1. OVERVIEW. For our discussion, it is useful to classify
DOS files into three general types:


EXECUTABLE, i.e., ???.EXE and ???.COM


DEVICE DRIVERS, e.g., ???.SYS or ???.DRV


DATA, e.g. ???.DOC, ???.TXT, ???.WQ1, etc.


2.1.1. DIET compresses EXECUTABLES and DRIVERS so that from the
user's perspective they perform the same as if they were not
compressed. That means you can execute them directly, or load
them from your CONFIG.SYS. We call this feature selF-eXtracting,
or SFX.


2.1.2. You can use DIET to compress DATA-type files, but they
are NOT self-extracting. To use DIETed DATA files, you must
either decompress manually or load DIET as a TSR so that they are
decompressed automatically when your application program loads
them.


2.1.3. To compress your files on the current directory, simply
type:
DIET filename,
or use wildcards, e.g.,
DIET *.*
When you use DIET without any options, EXECUTABLES and DRIVERS
are compressed as SFX, and all other files as non-SFX types
files.


2.1.4. To know whether or not a file has been compressed by
DIET, type:
DIET -l
That will display all files in the current directory, with com-
pressed files in reverse color.


2.1.5. To restore non-SFX compressed files to their uncompressed
status, type
DIET -r filename.ext, or DIET -r *.*


2.1.6. The simplest -- but not best -- use of DIET would be to
execute both of the following commands in a directory:
DIET *.*
followed by
DIET -r *.*
That would leave you with EXECUTABLES and DRIVERS in SFX mode,
and all other files (the DATA-type files) uncompressed.


To restore all DIETed files, including compressed executable or
driver files, type
DIET -ra filename.ext or DIET -ra *.*


2.2. DIET in TSR Mode.
We assume you're displaying DIET.DOC on your console, using
the DOS MORE command, Vernon Buerg's LIST.COM, or your favorite
Editor. Try the following:


(a) Return to DOS.


(b) Execute:
DIET DIET.DOC
That will compress this file. If you now try view the
file with MORE, or read it with LIST or your favorite
editor, you'll get garbage.



(c) Now Execute:
DIET -Z
That will load DIET in the TSR mode and allows you to
display DIET.DOC with MORE, LIST, or your Editor. Try
it.


(d) Remove the DIET TSR by executing:
DIET -ZR


(e) Finally, restore (i.e., decompress) DIET.DOC by
executing:
DIET -R DIET.DOC



3.0. USING DIET's OPTIONS


3.1. The basic DIET command structure is:
DIET [options] [file-names]
{wild-cards are OK in filenames}
Options require a prefix. You may use either "-" or "/" as the
option-prefix. Multiple options must be separated by spaces,
e.g.
DIET -z -p -td:\tmp



3.2. Options fall into two general categories:


(a) BASIC options that specify fundamental DIET functions,
and


(b) AUXILIARY Options that modify the operation of a BASIC
option.


3.3. The following table summarizes the BASIC and AUXILIARY
Options:

------------------------------------------------------------------
BASIC Function of the AUXILIARY Options that can
Option BASIC Option Be used with the BASIC option
------------------------------------------------------------------
DIET w/o Compress the named -X,-XC,-G,-D,-B,-K,-I,-A
option files -E, -Oxxxxx.
------------------------------------------------------------------
-R,-RA Decompress named files -Oxxxxx.
------------------------------------------------------------------
-Cxxxxx Copy without -R,-RA,-A
decompress/recompress
------------------------------------------------------------------
-L Identify compressed files.
-H Check integrity of compressed file, using CRC
------------------------------------------------------------------
-! Check DIET's own validity
-? Display Help Screen.
-$ Compress later (see -N)
------------------------------------------------------------------
-Z[n] Load DIET as a TSR. Value -P,-W,-N,-M
of [n] defines where in -S,-Txxxxxx
memory DIET is loaded.
------------------------------------------------------------------
-ZD Disable TSR DIET (also DIET OFF)
-ZA Activate TSR DIET (also DIET ON)
-ZR Remove TSR DIET from memory.
------------------------------------------------------------------



3.4. The following table summarizes what the file-related
AUXILIARY options do. Not included in the table are the
AUXILIARY options related to TSR-user of DIET -- they are dis-
cussed at xx, below. For more details on options, see the full
discussion of options at xx, below.

SUMMARY of what FILE-RELATED OPTIONS do.
-X Compress as SFX type.
-XC Force compression of a .COM file as a real SFX .COM file
-G Create a larger SFX header to speed up decompression
-D Force compression as DATA type.
-B Compare size in Byte count instead Cluster count
-K Recompress DATA files upon termination of the
application program that uses the files, but not while
the application program is running.
-I Ignore warning "may be overlay files!"
-Oxxxx Specify file name or path name of Output.
-A Set READ ONLY attribute of the file.


3.5. AUTOMATIC DECOMPRESSION BY USING DIET AS A TSR.
The general syntax for making DIET terminate & stay resident is:
DIET -Z[n] [options]
-Z loads DIET into memory as a TSR. If space is available
in upper memory (UMB), DIET will try to use it.
If Expanded memory is available, DIET will try to use it.
Under DOS 5.0, DIET -Z and DIET -Z1 achieve the same results.

-Z[n] the [n], if present, tells DIET how to use Expanded Memory.
-Z0 do not use Expanded Memory (same as -Z alone)
-Z1 use Expanded Memory for DIET's temporary files.
-Z2 use Expanded Memory for both DIET's temporary files
and for most of DIET's resident code, too. If you
have enough Expanded Memory, -Z2 saves you about 6k
bytes of regular memory.

-ZD disables DIET in memory, but leaves it loaded.
(DIET OFF does the same thing)
-ZA restores DIET after -ZD has been used.
(DIET ON does the same thing)
-ZR removes DIET from memory. But don't do that if you loaded
other TSR's after DIET.

AUXILIARY options available for use with BASIC option "Z" are:
-P automates recompression of DIETed file that has
been opened and changed.
-W automates compression of newly created file.
-N defers automated [re]compression until
DIET -$ is issued.
-M suppress messages in automated compression.
-S display decompressed file size
-Txxxx specify temporary work directory for DIET's use

Notes: After DIET has been loaded as a TSR, additional use
of "Z[n]" has no effect. But you can modify DIET's TSR
functions by using -ZD, -ZA, -ZR, or any of the AUXILIARY
options, by executing DIET [options] after having
loaded DIET as a TSR.

If you compress COMMAND.COM or some overlay files, you must
make DIET resident in memory.

Regular users of DIET should include DIET -Z in their
AUTOEXEC.BAT file. Alternatively, you can also load DIET
as a Device Driver, e.g.,
DEVICE=DIET.EXE -Z2 -P -K
That uses a few additional bytes of memory, but allows
you to DIET Device Drivers (to save disk space). If you
have large or many Device Drivers, that may be useful.

DIET's TSR function may be disabled if ^C or ^Break are used
while DIET is executing, or by certain interrupts. If DIET's
TSR function disappears for an unknown cause, try restoring it
by typing DIET -ZA at the command prompt.



4.0. Environment Variables.


4.1. In DOS versions 3.0 and above, DIET uses the following en-
vironment variable strings, if they are present. You create them
(usually from your AUTOEXEC.BAT file) as follows:
SET NameOfEnvVar = data


DIETOPT lets you define the options you want used as a default,
e.g.,
SET DIETOPT=-D -K
will use option -D and -K whenever a file is DIETed.
Options you can set with DIETOPT are: -J,-I,-D,-G,-K,-P,-W,-
N,&-S


DIETOFF DIET's ability to automate compression & decompression
can have certain undesirable effects. For some programs,
you may prefer to disable DIET, e.g., to speed up file
copying without having to use Option -C (see below in
Sec.5.0.). By including an environment string as below,
you tell DIET's TSR not to do what it usually would do
with DIETed files:
SET DIETOFF=COMMAND.COM;FC.COM;DUMP.EXE;XCOPY.EXE;LHA.EXE
You don't need to specify a Path for the files -- DIET is
concerned only with the programs' names.


NODIET You should suppress DIETing of some files, e.g., archives
like *.LZH and *.ZIP, and temporary intermediate files
created by some application programs. You can also tell
DIET to ignore all files in specified directories -- if
your NODIET string ends with a Directory name, be sure to
append a "\". There is a limit of 10 NODIET entries.
Example:
SET NODIET=*.LZH;*.ZIP;*.OBJ;C:\TMP\;C:\C600\
will suppress DIETing of all *.LZH, *.ZIP, *.OBJ files,
and of all files in directories C:\TMP and C:\C600.


TMP Define storage area for DIET's Temporary Files by putting
into your AUTOEXEC.BAT a line like:
SET TMP=E:\DirName (see also Option -T.)
NOTE: When you use DIET in resident mode, it creates and
uses temporary files with names such as __DIET__.??? DIET
cleans up after itself by erasing such files automatically
when DIET finishes its tasks, but if you boot your system
or stop DIET's execution by Ctrl-Break, such files may
remain on your disk. You can safely erase any such files.


DIETSIZE Some programs read in DATA files only to the size ob-
tained by the Function Call AH=4Eh/4Fh. The environment
variable:
SET DIETSIZE=xxxxxx.COM;xxxxx.EXE
enables such programs to fully read compressed MSG or HLP
files. Because some programs (e.g., SIDEKICK) check
DATA files by other methods, DIET cannot be used with
them. You'll have to experiment.



5.0. DETAILS ABOUT DIET's OPTIONS, in ALPHABETICAL ORDER


-! Makes a self-check of DIET.EXE's internal integrity.


-$ [Re]compress files whose automatic [re]compression was
deferred due to use of the -N option (see below). This
command is effective only if you specified -N in addition
to -P and/or -W when you invoked DIET as a TSR. The
DIET -$ command MUST be issued before you shutdown your
system -- it won't do it's job after a reboot.



-A Set Read-Only Attribute. Few users will need to use the
-A option, but it's there for those who want to be extra
safe. It is a safety measure for users who do not always
keep DIET in memory as a TSR. If you were to call a
DIETed file into your editor without DIET in memory, it is
possible that your editor could lock up. To restart you
would have to reboot, and you could lose your DIETed DATA
file. By using the -A option, you make any DIETed file
Read-Only.


-B Few users will need this option, but it's there for those
who do. If you don't fully understand the following
technical discussion, you don't need this option.
DIET will not compress files that would -- in their com-
pressed form -- use the same (or more) CLUSTERs of disk
space. (The size of CLUSTERS vary with disks e.g., on a
High-Density 5.25" disk each CLUSTER consists of 1,024
bytes). However, when you archive files with PKZIP or LHA
using those program's No-Compress options, you might want
to DIET them first to save as much space as possible.
The -B option tells DIET to compress the file even if the
number of CLUSTERS of the DIETed file is the same as the
un-DIETed version.


-C Copying DIETed files with DIET's TSR in memory takes extra
time because DIETed files are automatically decompressed
before copying and recompressed after copying. You can
suppress that by using DIET with the -C option to copy
files. The syntax is:
DIET -C

Example 1. To copy all files (including compressed files)
in the current directory of C:\ to Drive A:
DIET -CA:\ C:\*.*

Example 2. To copy compressed files in drive A: to Drive
C: and simultaneously decompress them:
DIET -RA -CC:\ A:\*.*
(See also the DIETOFF Environment Variable, above)


-D DIET forces compression of any file (incl. xxx.COM &
xxx.EXE) as a Data type. If DIET is loaded as a TSR, it
will decompress such files on-the-fly and will run them.
Why do this? What benefit can you get? Well, you can
save a little header space in that way (about 100 bytes
per executable file). More importantly, programs that
load themselves into high memory, and programs that use
many overlays, can be run while DIETed as Data types if
they won't run after you DIET them using the -I option.
As with certain other highly-technical options, if you're
confused by this, just don't use the -D option.


-E In its Default mode, DIET expands the file that is opened
by an application program into a temporary file, and erases
that temporary file at the termination of the application.
It is possible for WINDOWS 3.1 or some other DOS Task
Swapping program to confuse DOS' File Handles and erase
the original DIETed file instead of the temporary file,
even if the original file like (*.HLP or *.MSG files) was
set to R/O (ReadOnly). The -E option is designed to avoid
that risk. Use the -E option ONLY if you experience this
problem with a particular application.


-G You can speed-up self-extraction if you're willing to use
an extra 100 bytes (about 200 vs. 100) for the SFX header.
It's worth trying on large executable files, especially
when the 100 extra bytes don't change the number of
Clusters used by the DIETed file. We suggest you experi-
ment with this option and use it where it's to your
benefit.


-H Make an integrity check of a DIETed file using a CRC
algorithm, and determine whether the -K option was used
when the file was DIETed.


-I Ignore warnings. DIET ordinarily refuses to compress
files with overlays when the size of the file in EXEHDR is
not the same as the file's actual size, or when a file is
to be loaded into high-memory (e.g., ADDRV.EXE). But
since DIETed overlay files can be used when DIET is in its
TSR mode, you can use the -I option to force DIET to com-
press the files anyway.
DO NOT USE THIS OPTION UNLESS YOU LOAD DIET AS A TSR!!!


-J Ignore this option unless you are using JDOS4.0 from IBM-
Japan and can read Japanese.


-K Kill temporary Files Only on Quitting Program.
In its TSR mode, DIET opens a temporary file whenever a
program like an editor opens a compressed file. In its
default mode, DIET erases the temporary file when the
program closes it. Some programs open, close, and reopen
files frequently, e.g. a Help Message file, or communica-
tions software with overlay protocol files. That can be
very time consuming. To avoid that, DIET such files using
the -K option -- then the temporary files will be erased
ONLY when you quit the main program from which the DIETed
files were expanded.

-L [filename.ext] presents a directory listing for the
default disk, with the DIETed files in reverse color. An
"#" means the file has a self-extracting header, and a "*"
means it is compressed as a DATA file. If you add a
filename and filetype, you restrict the search to the
defined files. Wildcard filenames are OK, e.g.,
DIET -L *.EXE
DIET -L's default is the same as DIET -L *.*


-M If you don't want DIET to give you a message about what it
is doing to your file, suppress the message with -M


-N When the -W and/or -P options are specified when DIET is
loaded as a TSR, DIET automatically compresses newly
created files and recompresses files that are not set to
READ ONLY. Specifying the -N option when DIET is loaded
as a TSR delays auto-compression and recompression until
DIET -$
is issued to instruct DIET to recompress changed files
and/or compress newly created files. The time stamp of
the compressed files is set to when they were closed, NOT
to when they were actually compressed. This option is
useful if you don't want DIET to take time to recompress
files as you work, but prefer to have DIET do its job when
you're ready to quit. The DIET -$ command works only if
you use it BEFORE you reboot.


-O By default, DIET overwrites the files it compresses (or
uncompresses). If you want to save the uncompressed (or
compressed) file, use the -O option to put the changed
file into another directory. To illustrate:

Example 1. You are NOT logged into DRIVE A:. You want a
compressed version of A:ALPHA.DAT in your default
directory:
DIET -O A:alpha.dat.

Example 2. You want to compress ALPHA.DAT in your default
directory and store the compressed file in directory C:\TMP
DIET -OC:\tmp\ alpha.dat
(note the positions of the spaces and back slashes!!)


-P Use this option to automatically recompress changed DIETed
files, because in its default mode DIET does not re-
compress DATA files that were changed after being loaded
and manipulated by a program such as an Editor or a
Spreadsheet. DIET -P enables automatic recompression.
Note: DIET's ability to automatically recompress DATA
files depends on your Editor's internal workings.
Experiment!


-S Some application programs read in a specified amount of
data from overlay or other files, and get confused if
those files have been DIETed. Specifying the -S option
when DIETing avoids that problem. We suggest ALWAYS using
the -S option if you are going to archive files using LHA,
PKZIP, or PKARC. There are no circumstances in which it
is disadvantageous to use the -S option -- we suggest
using -S when invoking DIET as a TSR.


-T In its default mode, DIET stores in the default directory
certain temporary files that it creates and needs. If you
use the Environment Variable TMP=??? (as may be required
by various programs), DIET will attempt to store its tem-
porary files in the directory that you've defined as ???.
To force DIET to use a particular directory for its tem-
porary files, use the -T option on the DIET line in your
AUTOEXEC.BAT file, e.g.
DIET -Z2 -TD:\tmp1\
DO NOT FORGET THE LAST "\" IN THIS OPTION.
The -T option is especially useful if you define a RAM
DISK directory as the recipient of DIET's temporary files.


-W Automatically DIETs all newly-created files, including any
temporary files that your programs may create. That can
be useful but can also waste time. To avoid this option
becoming a nuisance, use the NODIET Environmental Variable
to suppress DIETing of files like *.OBJ, *.LZH. Or use -N
option together, and issue the command
DIET -$
before you quit your session.


-X As a default, DIET recognizes as device drivers all files
with the extensions "SYS" or "DRV" and does NOT compress
them. If you want to DIET a Device Driver, you must make
it self-extracting (because you won't have DIET in memory
as a TSR until you load it as a TSR in your AUTOEXEC.BAT
file). You can force DIET to add a self-extracting header
to any file by using the -X option. But see also option
-I, above.


-XC DIET always compresses a .COM file into .EXE file and
renames it as .COM. You need not be concerned about this.
If you have a particular reason to want DIET to produce a
real .COM file, you can force that by using this option.
But be sure to experiment -- the behavior of such a .COM
file may be unpredictable.


-Z[?] See Sec.3.5., above.



6.0. CONCLUDING REMARKS.


6.1. Don't allow DIET to be memory-resident when using HardDisk
Managers like SPEEDDSK, OPTIMIZE, DOG. Disable DIET by executing
DIET -ZD when you use such programs!! In fact, it's always best
to clear ALL TSRs before using such programs.


6.2. If you elect NOT to make DIET memory-resident:


(a) Remember to manually decompress Data-type files before
using them. You could simplify that by using Batch files
to decompress the Data-type files and then invoking your
application program from the Batch file.


(b) When using a Laptop with a Ramdisk, a useful technique is
to store your application program and related Data files
on a floppy and transfer them to the Ramdisk (e.g.,
Drive D:) with:
DIET -r -CD: a:*.*
When you're done, exit from the application program and
do:
DIET -CA: D:*.*
That will compress the revised Data files and store them,
together with the application program, on A:. Of course,
you must have enough room on A: to accept the revised
files.


6.3. With DIET memory-resident:


(a) Specifying a RAM disk for DIET's temporary files speeds
up DIET's operation -- see the -T option, above.


(b) You may see a message like: "Can't find abc.exe" even
though the file exists. This is usually the result of
DIET being unable to find enough space in your temporary
directory for its temporary files. Check the space in the
appropriate directory (the Default directory, of the
defined TMP directory) if you get this message.


(c) DIETOPT variables modify DIET to avoid certain un-
desirable effects, like decompressing files before copy-
ing them and then recompressing those files after
copying. To optimize DIET's performance in YOUR
application, experiment with the -C, -P, -W, and -K
options.


(d) Word processors frequently write files back to disk
before you exit them, and create auxiliary files for
formatting or controlling a printer. If you use the -P
option, that can take a lot of time for compressing and
decompressing these files. By specifying the -K option,
you defer all that DIETing until you exit the word
processor. If you have plenty of space on your Hard Disk
or Ram Disk, it's easiest to specify -K when you load
DIET as a TSR. If you're short of disk space, be selec-
tive about the files that are DIETed with the -K option,
by specifying -K when you DIET files that you want to
remain expanded until you quit a particular application
program.


(e) The -P option is highly-desirable when you always use
DIET as a TSR, especially when appropriately used in
conjunction with -K. You may enjoy being reminded of the
space you're saving when you quit your application (DIET
tells you what it's doing). If you don't want to be
reminded, use the -M option to tell DIET to do its work
quietly.


(f) You can force DIET to compress executable files that use
overlays (and the overlays themselves) when you use DIET
as a TSR. To do that, use the -K option and the -D op-
tion when DIETING such files.


(g) You can toggle DIET on and off with "DIET ON" and DIET
OFF". Those commands also tell you the status of various
options.


(h) DIET tries to keep track of filenames even with DOS 5.0's
task-swapping, or Windows in its enhanced mode. However,
you may find some application programs for which DIET
fails to trace tasks swapped. Take due precautions with
task swapping -- experiment before relying on using DIET
with them.



7.0. DISTRIBUTION AND COPYRIGHTS


7.1. Distribution Policy. DIET.EXE and all documents packed
with it are copyrighted by Teddy Matsumoto. The package consists
of DIET.EXE, DIET.DOC, DIETTECH.DOC, DIETAPI.DOC and
HISTORY.DOC. No copyright is claimed for files that have been
DIETed.



7.2. DIET may be copied, distributed, and used free of charge
for PERSONAL use. Licenses for commercial use must be obtained
from Teddy Matsumoto PRIOR to making commercial use of DIET.



7.3. Except for a nominal fee for materials and postage, no one
may charge for copying or distributing DIET. DIET may be dis-
tributed only as a complete package. BBS and disk distributors
should be prepared to distribute up-dates and fixes as such may
be released. The author will appreciate being advised by BBS
operators and disk distributors that they are distributing DIET,
so that he can try to assure that they received fixes and up-
dates.


7.4. CONTACTING THE AUTHOR. In Japan, Email to Teddy Matsumoto
at GBG00230 on Nifty Serve.
Overseas Users may contact K.Okubo at one of the following:
[email protected]
GEnie: K.Okubo
INTERNET: [email protected]


This English Version of DIET.DOC was prepared by K.Okubo, with
editorial assistance from Eric Stork (STORK on GEnie).



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