Re: more on SAS data files

[Ben Pfaff]

Jason Stover <address@hidden> writes:

> I put them on the same page that describes the test data files.
> The whole thing is now at
>
> http://math.gcsu.edu/~jhs/sas/

I searched around the net for some more sample SAS files and
discovered a little bit more semi-obvious stuff.

Offset 0xd8 apparently contains 8 bytes of ASCII version
information on the SAS version that wrote it, e.g. "9.0101M3" or
"8.0202M0".

Offset 0xe0 apparently contains somewhere between 8 and 32 bytes
of operating system name, padded on the right with null bytes,
e.g. "XP_PRO" or "WIN_ASRV".  I say "between 8 and 32" because
the longest example I have is 8 bytes of text, but all of them
are padded out to at least 32 total bytes with nulls.

Offset 0xa4 almost certainly contains the date and time at which
the file was created, because sorting the files by the bytes in
the 8 bytes starting there causes them to be put into a
reasonable order of creation.  I'd assume that it was written as
an IEEE 8-byte float in seconds since Jan 1, 1960, since that's
the format that SAS uses internally anyhow, but by my
calculations that would mean that your sample files were created
sometime around March 21, 2007, which I assume is over a year
off, so something is fishy here.

Offset 0xac has 8 bytes that are identical to those at offset
0xa4.  Perhaps there's a "creation date" and a "modification
date" or whatnot.

That's all I have time for tonight.
-- 
Ben Pfaff 
http://benpfaff.org