Re: more on SAS data files

[Jason Stover]

I put the information on the SAS data file format on the new
PSPP wiki: http://jstover.motd.org. I will keep the wiki updated
and no longer update the old page at math.gcsu.edu.

-Jason

On Sat, May 31, 2008 at 12:03:07AM -0700, Ben Pfaff wrote:
> 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