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Q74464: Pipe (|) After IF EXIST Fails

Article: Q74464
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:5.x,6.0,6.2,6.21,6.22
Operating System(s): 
Keyword(s): 
Last Modified: 17-DEC-2000

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The information in this article applies to:

- Microsoft MS-DOS operating system versions 5.0, 5.0a, 6.0, 6.2, 6.21, 6.22 
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SUMMARY
=======

There is a known problem with the pipe (|) command that causes the pipe to fail
when used after an IF EXIST statement. For example, the command

  IF EXIST c:\dos\readme.txt TYPE c:\dos\readme.txt | MORE

normally displays the contents of C:\DOS\README.TXT one screen at a time. When
this command is issued under MS-DOS 5.0, 6.0, or 6.2 no information is displayed
and you are returned to the prompt, even though the file exists.

In addition, this command results in File Allocation Table (FAT) corruption on
the drive that the TEMP environment variable is pointing to or on the current
drive if no TEMP variable has been set. Running CHKDSK after this command shows
there are "<x> lost clusters in 1 chain," where <x> is dependent
upon the size of the file being processed by the pipe. (The number of lost
clusters and chains might be larger if there was additional FAT corruption prior
to using the pipe.) The FAT corruption caused by this command does not result in
data loss, and you can use CHKDSK with the /F switch to correct the corruption.

Please refer to the "Microsoft MS-DOS User's Guide and Reference" for more
information on the use of the CHKDSK command.

Microsoft has confirmed this to be a problem in MS-DOS versions 5.00, 5.00a,
6.00, 6.20, 6.21, and 6.22. We are researching this problem and will post new
information here as it becomes available.

Additional query words: 6.22 5.00 5.00a 6.00 6.20 batch

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Keywords          :  
Technology        : kbMSDOSSearch kbMSDOS621 kbMSDOS622 kbMSDOS620 kbMSDOS600 kbMSDOS500 kbMSDOS500a
Version           : MS-DOS:5.x,6.0,6.2,6.21,6.22

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