Using NT registry calls to solve CR-LF issue with text files.
John E. Malmberg
wb8tyw at qsl.net
Sun Feb 6 21:23:24 GMT 2000
Beau Kuiper <ekuiperba at cc.curtin.edu.au> wrote:
> On Sun, 6 Feb 2000, John E. Malmberg wrote:
> > The mention of looking up performance data from the registry gave me an
> > idea.
> > With the registry calls that you can do now, is it possible or practical
> > look up the file type in HKEY_CLASSES_ROOT before it is transferred, and
> > it is registered as a known text type to translate the CR-LF information
> > the file is being transferred?
> > Just a thought.
> A very evil thought. They tried to do that with the linux msdos filesystem
> support. It really stuffed life up for many people with scilent data
> corruption. To do the same with samba would be not to learn from the
> mistakes of others. to be specific: YOU CAN NEVER DETERMINE WHAT IS STORED
> IN A FILE GIVEN THE NAME OF THE FILE :-)
Windows actually uses two methods of determining a file type. The first is
a registry, and the second is to examine the first two bytes of the file for
a signature. Some programs use the signature over the file type.
Somewhere there is a list of these magic codes, but I can not recall where
it is at the moment. This is how programs like WORD, WORDPAD, and WRITE
determine how to translate a document. I am not sure if there is a master
list somewhere that Windows maintains for these signatures, or if they are
hard coded into each application as needed.
If someone does know of a good reference for these signature bytes that is
available on-line, on Technet, or MSDN, I would like to know where it is.
It would certainly be evil if it was manditory, but it could be very useful
as a per-share option. And definitely not the default option, but there for
system administrators to enable after they have read the warnings.
Even with reading a table from the Windows registry there could be problems.
On OpenVMS a file name xxxxx.COM is a text shell script. On Windows, it is
a binary executable. This is where the magic codes could be of some help.
As for my situation, with the OpenVMS operating system, If I do not do some
translations, I can not pass most text files created on OpenVMS to LANMAN
The default native OpenVMS text file format can not be understood by a
It is relatively easy to detect some of the text file formats on OpenVMS and
send them over the wire correctly. For all others they must be sent as
On sending a file from Windows to OpenVMS, I also need to know / guess how
to translate the file format, or the file may only be usable by the Windows
The only clue to go by that I have easy access to is the file type. If a
call was made to the Windows registry, then I would not have to maintain my
own table. A database of the magic codes would also assist in this task.
The reason I bring this up as a platform independent issue, is the
complaints from people on the regular samba list about this on the UNIX
Remember the average user thinks all this stuff works by magic.
wb8tyw at qsl.net
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