One little endian question

[Jeff Harrison]

--- "Brian K. White" <brian at aljex.com> wrote:

> Maybe you can perform an empirical test.
> 
> Ship the app with a file that has a known value if
> read on little-endian.
> Read the file and test if the value is what you
> expect.
> You can do all that behind the scenes as part of a
> setup procedure.
> 
I don't think this would work without some additional
test for endianness.

> You could probably create the test data on the fly
> even.
> Use file i/o or something to write out an explicit
> string of bytes that 
> forms a valid structure of some sort in
> little-endian
>

Oh, very good!  I think you are on to something here. 
All I would need to do would be to write a free record
in a filepro file, then examine the 20 byte header for
the @cd and make sure it is today's date - then store
the appropriate endianness that I used to get the
valid date.  

> The test data/file probably doesn't necessarily have
> to be a filepro 20 byte 
> header.
> It can be anything that filepro will read according
> to the endianness of the 
> platform.
> Is ordinary data in files subject to that? ordinary
> strings?

I think it is only an issue with binary data - not
strings.

>... maybe you don't 
> even have to write a file, just create a string and
> then interpret it with 
> some filepro function? Thats desireable for another
> reason, if you ship the 
> app with a special test file, you'd have to watch
> out for xfer having 
> "fixed" your test file!
>

Not an issue if I create the data on the fly as you
mentioned above.

[snip]

>... I dare say none of 
> us has any endianness tests in our normal apps and
> we survived this long :)
> 
> -- 

Yes, apparently I am going where no man has gone
before :-)

Thanks!

Jeff Harrison
jeffaharrison at yahoo.com

Author of JHExport and JHImport.  The fastest and
easiest ways to generate filepro exports and imports.


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