[fitsbits] keyword order

[Arnold Rots]

We use a formatting convention for our HISTORY keywords that allows
full reconstruction of the scripts that generated the file.  It
includes a sequence number in columns 73-80.

  - Arnold

William Pence wrote:
> 
> Tom Kuiper wrote:
> > 
> > Noted that keyword order is not guaranteed.  Thanks for that advice.
> > 
> > I'm concerned about the COMMENT and HISTORY keywords.  If a comment or
> > history entry exceeds 72 characters, it must span two or more header entries.
> > One would not like to see these garbled.  How can one avoid this?
> 
> In practice, most software does preserve the keyword order, so it will
> probably be OK to implicitly assume that the order and position of the
> COMMENT and HISTORY keywords is significant, at least for human readers of a
> listing of the header.  I seem to recall seeing some FITS files where the
> COMMENT or HISTORY keywords contained a sequence number (or maybe a time
> stamp) so that the order was explicitly defined, but this is not typically
> done.
> 
> Bill Pence 
> -- 
> ____________________________________________________________________
> Dr. William Pence                          pence at tetra.gsfc.nasa.gov
> NASA/GSFC Code 662         HEASARC         +1-301-286-4599 (voice)     
> Greenbelt MD 20771                         +1-301-286-1684 (fax)
> 

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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 81                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head-cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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