Announcement

**OTTO WIPFEL** · 26 Mar 2002, 11:45 AM

My way of Archiving multiple files from within one of my PB DOS 3.5
programs written for clients is to simply:

SHELL "PKZIP C:\ARCHIVE\ARCH-ZIP Files.* FileA.Dat EtcFiles.*"

Vary the PKZIP Commandline Params according to your needs.

Oooops ! Forgot that this works in Pure Dos only. In Windows it causes
an "Illegal Operation" Shelled from the DOS program but not when invoked
from the Windows DOS Prompt.

[This message has been edited by OTTO WIPFEL (edited March 26, 2002).]

**Michael Mattias** · 26 Mar 2002, 12:42 PM

Assuming your file is laid out something like this:
Header
Data
Header
Data
Header
Data
...

Code:

TYPE FileHeaderType
   FileName  AS STRING * 30
   FileLen   AS LONG
   OtherControlData AS yadda,yadda,yadda
END TYPE

DIM  FH AS FileHeaderType

OPEN "Big_File" FOR BINARY AS #1 
Seek # 1, 0
DO
   GET #1,,FH                 'read header and advance 
   GET$ #1,FH.FileLength,X$   'get the file data as a string (X$)
   CALL ProcessFileData (X$)  'do something with it
LOOP UNTIL SEEK(1) >= LOF(1)  ' might be =, might be >=
CLOSE #1

There are variations, but this should work.

MCM

**Lance Edmonds** · 26 Mar 2002, 03:18 PM

Originally posted by OTTO WIPFEL:
Oooops ! Forgot that this works in Pure Dos only. In Windows it causes
an "Illegal Operation" Shelled from the DOS program but not when invoked
from the Windows DOS Prompt.

I use SHELL to PKZIP.EXE under all versions of WIndows, including XP and it works fine for me... and believe me, if it didn't I'd hear about it pretty promptly!

Anyway, your comment suggests something else is wrong there Otto. Remember that in a SHELL, conventional memory could be quite low, and this could conceivably cause problems for PKZIP (or any target APP)...

If you are not using UltraShell to free conventional memory before the SHELL starts, have you tried using some of the PKZIP "trouble shooting options" to selectively disable EMS/XMS/HMA/UMB/DPMI when run on your test machine? One of those options may give you the hint you need to fix the problem.

That said, I have not (and do not) use any of those options in my DOS apps that SHELL to PKZIP.EXE under Windows.

However, I do remember a problem a problem with Novell PNW that would cause PKZIP to crash much like you describe above... IIRC, the cause was the DPMI handler in PNW. Maybe your test machine(s) have similar problems?

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Amos Vryhof** · 26 Mar 2002, 03:36 PM

It seems that Michael is the only one that actually got what I was
saying. That looks like the solution I need too. (well a variant
anyway)

Since I have to do it that way anyway, I'm going to add more
features to the file format...such as attributes and the like.

I'll just have to rewrite the archive and unarchive functions.
(no problem really)

For Otto and Lance, who suggest PKZIP. I am doing an installer
for an OpenSource project, and see no point in distributing a
shareware program (PKUNZIP) with it.

Besides, it's good to learn new things. It's also good to have
an archiver library to just plug in to programs where I need it.

------------------
Amos
mailto:[email protected][email protected]</A>

**Amos Vryhof** · 26 Mar 2002, 08:54 PM

Thanks Michael, it works perfectly now! I will give you credit
in the comment block at the top of the code, and in the readme.

------------------
Amos
mailto:[email protected][email protected]</A>

**Lance Edmonds** · 27 Mar 2002, 01:39 AM

Glad you found a solution (Michael's variable-length-record database scheme).

However, to be clear, I never actually recommended any method for your question... I was only responding to Otto's message that using PKZIP.EXE under Windows reportedly did not work...

That said, I prefer to use self-extracting archives that my custom installer app launches. LHA and RAR seem to work pretty well. That way there is no additional app to distribute - you simply include a 'SFX-style' archive in your distribution set. Licensed appropriately of course.

Another benefit is that these compression apps include all kinds of useful features and CRC testing... which may save you significant time writing from scratch.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**OTTO WIPFEL** · 27 Mar 2002, 01:45 AM

AMOS - I also believe in doing my own thing
====
That's what got me started programming 20 years ago when, being an Accountant,
I could not find Accounting Software to do what I wanted it to.

What you are doing is way above my head. As my son, Novell's Clustering Architect,
excuse me for advertising , keeps saying "Why try re-inventing the wheel". There
is no way I can do better than PKZIP, I have a licensed version 2.05 of.

LANCE: Once again, your invaluable experience can help me solve a long standing
====== puzzle, I worked around by giving my Accounting Software clients using it
in Windows a Batch file to run from the DOS prompt or via a Desktop Shortcut.

Your comment prompted me to have a closer look at the problem. Testing a stand
alone version of my Archiver, usually EXECUTED into by the MENU.EXE, I got no
problem. The moment I ran it as part of my Accounting Software System, I did !

It's BTRIEVE's DOS/4G Protected Mode Run-Time / Switch program !

Code:

Modules using memory below 1 MB:

  Name           Total           Conventional       Upper Memory
  --------  ----------------   ----------------   ----------------
  SYSTEM      41,312   (40K)     15,008   (15K)     26,304   (26K)
  HIMEM        1,168    (1K)      1,168    (1K)          0    (0K)
  EMM386       4,320    (4K)      4,320    (4K)          0    (0K)
  WIN          2,336    (2K)      2,336    (2K)          0    (0K)
  vmm32      105,488  (103K)      1,392    (1K)    104,096  (102K)
  SBEINIT      4,480    (4K)      4,480    (4K)          0    (0K)
  COMMAND     11,056   (11K)     11,056   (11K)          0    (0K)
  ADMMENU      1,088    (1K)      1,088    (1K)          0    (0K)
  PMSWITCH    57,904   (57K)     57,904   (57K)          0    (0K)
  COMMAND     10,688   (10K)     10,688   (10K)          0    (0K)
  ADMARCHV   145,760  (142K)    145,760  (142K)          0    (0K)
  COMMAND     10,688   (10K)     10,688   (10K)          0    (0K)
  ANSI         4,320    (4K)          0    (0K)      4,320    (4K)
  IFSHLP       2,864    (3K)          0    (0K)      2,864    (3K)
  COMMAND     13,776   (13K)          0    (0K)     13,776   (13K)
  KEYB         6,944    (7K)          0    (0K)      6,944    (7K)
  Free       389,184  (380K)    389,184  (380K)          0    (0K)

Memory Summary:

  Type of Memory       Total         Used          Free
  ----------------  -----------   -----------   -----------
  Conventional          655,360       266,176       389,184
  Upper                 158,304       158,304             0
  Reserved                    0             0             0
  Extended (XMS)     66,885,024             ?   534,974,464
  ----------------  -----------   -----------   -----------
  Total memory       67,698,688             ?   535,363,648

  Total under 1 MB      813,664       424,480       389,184

  Largest executable program size         373,920   (365K)
  Largest free upper memory block               0     (0K)
  MS-DOS is resident in the high memory area.

The above taken SHELLED from within the Archiver.

Any idea how to solve that one ?
========================

------------------

[This message has been edited by OTTO WIPFEL (edited March 27, 2002).]

**Amos Vryhof** · 27 Mar 2002, 07:14 AM

Arrgh! It was working at first, now I seem to be getting a file
not found error when I try to write the file out.

The code I am using is

Code:

TYPE headerType
    fileName        AS      STRING*30
    FileLen         AS      LONG
END TYPE

DIM  FH AS headerType
dcf%=FREEFILE
OPEN arcFile$ FOR BINARY AS #dcf%

Seek #dcf%, 0
DO
        GET #1,,FH
        print "Found file: ";FH.fileName
        tf%=FREEFILE
        ON ERROR RESUME NEXT
        outFile$=trim$(FH.filename)
        open outFile$ for BINARY as #tf%
                IF ERR=53 then
                        print "Error: ";outFile$
                        EXIT LOOP
                end if
        GET$ #dcf%,FH.FileLen,X$
        PUT$ #tf%, X$
        close #tf%
LOOP UNTIL SEEK(dcf%) >= LOF(dcf%)
close #dcf%

Which is quite similar to Michael's, since I haven't added any
features (attributes, etc) to the initial test functions.

A few things I have tried are

Writing a function that opens the file, writes a space to it
then closes it back up before opening the file for BINARY.
Changing to different directories to write the file.
Restarting my computer (sometimes works)

I have never had this problem with output files before...so I
must have something wrong. Any ideas?

If anyone needs the full source, please ask. It's all open
source so there are no "trade secrets" in it or anything.

------------------
Amos
mailto:[email protected][email protected]</A>

**Michael Mattias** · 27 Mar 2002, 08:59 AM

Check for nulls (CHR$(0)) in FH.Filename (or trim with ANY CHR$(0,32) to remove trailing spaces <U>and</U> nulls.)

When you create the FH.Filename member,remember to use LSET instead of simple assignment(=)in order to insure spaces rather than nulls throughout the member.

MCM

[This message has been edited by Michael Mattias (edited March 27, 2002).]

**OTTO WIPFEL** · 27 Mar 2002, 09:25 AM

LANCE:
=====

PKZIP -3 -), disabling 32bit support did the trick

Thanks.

------------------

**Lance Edmonds** · 27 Mar 2002, 04:54 PM

First, try opening the files with LOCK SHARED access.

Next, and in addition to Michael's comments, your code appears not to be testing the error 53 condition after opening the 1st file, and an error here may propagate through the code.

The 'fix' is to test ERR after the first OPEN statement, and also to use ERRCLEAR right before the OPEN statement in the loop... that way an ERR 53 after the 2nd OPEN can definitely be attributed to that statement (otherwise the point of failure cannot be readily attributed).

That is, ERR/ERRTEST is only set when an error occurs... it is not cleared when a subsequent statement executes correctly. Therefore, use pleanty of ERR testing, but do it at appropriate places in the code. Also, don't be afraid of using ERRCLEAR at the start of 'critical' blocks of code either. In your code above, you only test the 2nd OPEN statement for an error, but no other file I/O statements are error tested.

Finally, you should be able to move the ON ERROR RESUME NEXT statement outside of the loop.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Lance Edmonds** · 27 Mar 2002, 05:00 PM

Otto: excellent news!

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Amos Vryhof** · 28 Mar 2002, 10:45 AM

With a little more research, and everyone's tips, I finally got it
working. I can now compress and archive files, then decompress them.

The filename problem was in fact a chr(32) at the beginning of the
data. That was easily fixed. I also took Lance's suggestions and
added more error checking.

I will comment the code tonight, and post it for everyone's access
later. After the project I am using it in is finished, I will
also learn more about LHA's optimizations to the Huffman Codes
and optimize in a similar manner.

Keep a lookout for smaller archives, smaller executables, and more
features (SFX, Attributes, Pathnames, etc)

------------------
Amos
mailto:[email protected][email protected]</A>

**Lance Edmonds** · 29 Mar 2002, 01:59 AM

Good news Amos... Thanks for letting us know!

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

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