Re: Copy with Verify?

rmace wrote:
Ok; but what about the info from microsoft?
Does the following only apply to the old real versions of DOS and not
to the current DOS emulators on Windows XP? From:
http://support.microsoft.com/kb/126457

Your information (KB) is correct. I don't know what XP's version of copy
and xcopy do but that's true of the old DOS operating sytems up thru win98.
I hesitate to correct Wesley because he's seldom wrong about anything,
but it's still my impression that they operate that same way under XP, but
.... I only base that conclusion on the length of time it takes to copy or
copy/verify. An actual full data verification will take about the same
length of time to accomplish as the copy operation itself. Empirical and
admittedly very rudimentary tests I just tried seem to tell me that there is
NO data verification as far as comparing the destination data to the source.
Copying a 40 Meg file results in almost no noticeable change in copy time
with or without the data verification switch.

So perhaps what I should be doing is aking Wesley: Please comment/clarify
the information because I know the KB article is correct for the old DOS
versions. My experience doesn't seem to bear out those comments Wesley made
however.
Perhaps the confusion is between using the Command Prompt to issue actual
copy/xcopy commands vs. the Windows method of copy? Or ... ?

Pop`





"VERIFY ON, COPY /V, XCOPY /V Commands Do Not Compare Data
Article ID : 126457, Last Review : May 6, 2003, Revision : 2.0
Some versions of the MS-DOS "User's Guide" and online Help indicate
that the /V (verify) switch for the COPY and XCOPY commands actually
compares the source and destination files to determine whether they
are identical. This is not correct. The /V switch verifies that the
destination file, once written, can be read. No comparison of the
files occurs.
This information also applies to the VERIFY ON command.
When you use the VERIFY ON command, or the /V switch with the COPY or
XCOPY command, the MS-DOS file system uses the block device driver
command code function 09H, Write with Verify. This verification
process consists of confirming that the data just written can be read
(for example, that the data was not written to a bad sector on the
disk). No comparison of the source and destination data occurs.
To compare the source and destination files, use the MS-DOS FC (file
compare) command after you use the COPY or XCOPY command.
REFERENCES
For more information about the VERIFY, COPY, XCOPY, or FC command,
see your MS-DOS "User's Guide," or use the online Help in MS-DOS
versions 5.0 and later."

I honestly do not know. I am asking, not telling.

I was under the impression that "verify" just checks that the new
file is readable, not that it actually matches the source.

Then you had the wrong impression.

/v Verifies each file as it is written to the destination file to
make sure that the destination files are identical to the source
files.

Xcopy HELP
Paste the following line into Start | Run and click OK...

hh ntcmds.chm::/xcopy.htm

Also type: xcopy /? in a command prompt.

--
Hope this helps. Let us know.

Wes
MS-MVP Windows Shell/User

In news:54DA5387-5A90-4C4D-BC8C-868392FF756D@xxxxxxxxxxxxx,
rmace <rmace@xxxxxxxxxxxxxxxxxxxxxxxxx> hunted and pecked:
I was under the impression that "verify" just checks that the new
file is readable, not that it actually matches the source.
--
Bob


"Talal Itani" wrote:


Under DOS, xcopy has a verify switch. When I copy in XP, is there
a verify option? Thanks.

T.I.



.

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