Q136995: How the Visual FoxPro Setup Wizard Compresses Large Files

Article: Q136995
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0
Operating System(s): 
Keyword(s): 
Last Modified: 12-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
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SUMMARY
=======

The FoxPro 2.6 Setup Wizard had some limitations when it distributed large
files. The Visual FoxPro 3.0 Setup Wizard has improved capabilities. This
article describes how large files are handled and ways to customize the handling
of large files.

MORE INFORMATION
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When the Setup Wizard compresses files for assembly into disk images, it ensures
that the files do not exceed the limit (in bytes) defined by the SplitSize value
in the Preferences section of Wzsetup.ini. By default, this value is 363,520.

Files that fall below this limit are renamed with a $ in the filetype. For
example, a 234,738-byte file named Mydata.dbf is compressed into:

  MYDATA.DB$    61,638

Files that exceed this limit are chopped into pieces. The pieces are given a
generated filename and an extension that indicates the order in which they are
re-assembled when installed on the target computer. For example, a
4,415,168-byte file named Mydata.fpt might be divided and compressed into:

  56600245.001   263,446
  56600245.002   344,833
  56600245.003   335,156
  56600245.004   323,052
  56600245.005   273,779

During installation on the target computer, these files are decompressed and
reassembled into Mydata.fpt.

If you need to reassemble this table without running the setup program, you can
use Expand.exe to expand each piece; then copy the expanded pieces of the memo
file into the final memo file:

  EXPAND MYDATA.DB$ MYDATA.DBF
  EXPAND 56600245.001 MYDATA.001
  EXPAND 56600245.002 MYDATA.002
  EXPAND 56600245.003 MYDATA.003
  EXPAND 56600245.004 MYDATA.004
  EXPAND 56600245.005 MYDATA.005
  COPY MYDATA.001+MYDATA.002+MYDATA.003+MYDATA.004+MYDATA.005 MYDATA.FPT

To determine the original name of a compressed file, refer to the Application
section of the Setup.inf file that is written to DISK1 (or NETSETUP) of the disk
image directories:

[Application]
"56592553"=1,MYDATA.DB$,,,,,,,,!READONLY,,MYDATA.DBF,,,,234738,,,,,VITAL
"56592734"=1,56600245.001,,,,,,,,!READONLY,,MYDATA.FPT,,,,727040,,,,,VITAL
"56592734"=1,56600245.002,MYDATA.FPT,,,,,,,!READONLY,,,,,,952832,,,,,VITAL
"56592734"=1,56600245.003,MYDATA.FPT,,,,,,,!READONLY,,,,,,953856,,,,,VITAL
"56592734"=1,56600245.004,MYDATA.FPT,,,,,,,!READONLY,,,,,,982528,,,,,VITAL
"56592734"=1,56600245.005,MYDATA.FPT,,,,,,,!READONLY,,,,,,798912,,,,,VITAL

The default SplitSize value of 363,520 is held over from the FoxPro version 2.6
Setup Wizard, which was able to generate 360K disk images and needed to ensure
that files would not exceed the capacity of a 360K disk. While the version 3.0
Setup Wizard does not generate 360K disk images, the SplitSize value of 353,520
provides improved flexibility when assembling files into 1.2-MB and 1.44-MB disk
images.

The version 3.0 Setup Wizard is able to split a file into hundreds of pieces by
using a numeric file extension. The file extension may extend from 001 to 999,
but a directory limitation (or setup limitation) may be encountered before
getting that far.

The SplitSize setting may be increased to cause the Setup Wizard to create larger
chunks when it splits large files. Do this by modifying the SplitSize setting in
Wzsetup.ini. Do not use a setting greater than the number of bytes that will fit
on 1.2-MB disks (or 1.44-MB disks). Some experimentation and testing may be
required to arrive at settings that work well for the specific application.


Additional query words: VFoxWin

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : WINDOWS:3.0

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