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Re: Hmmmm. Can rad handle the new 88d stuff yet? (decoder?)


I have not had a chance to look at the data yet, but I think Bob's 
observation may be the key.  ZLIB always refers to the compression
scheme used by gzip (because gzip uses zlib). 


On Mon, 6 Nov 2000, NIMBUS Librarian wrote:
> 
> Folks,
> 
> Don't forget that you need to account for the WMO header
> at the front of the data... it's not compressed, so it'll
> need to be stripped out first.
> 
>      Bob Lipschutz
>      FSL
> 
> 
> > 
> > In a previous message to me, you wrote: 
> > 
> >  >
> >  >Pete...
> >  >
> >  >You are trying to make things too complicated.  Most data compression 
> > progr
> ams
> >  >have some easy of way of sending uncompressed data to stdout.  The ones 
> > tha
> t
> >  >I know about are:
> >  >
> >  >  Scheme          Command to use
> >  >  pack            pcat
> >  >  compress        zcat
> >  >  gzip (ZLIB)     gzcat or zcat (depending on how it was built)
> >  >  bzip2           bzcat
> >  >
> >  >The only one that I can't find a way, (at least via the man pages that I 
> > ha
> ve)
> >  >is "zip".
> >  >
> >  >As a sample:
> >  >
> >  >  cat file.gz | gzcat
> >  >
> >  >would get you the ungzipped version of "file".
> > 
> > Hi Kevin,
> > 
> > That's not exactly the problem here. The NEXRAD files are not
> > zip'd files, they just happen to use one of the same compression
> > algorithms that zip does.  They are not in 'zip' format, so
> > the stdio version (funzip on unix) doesn't recognize them.
> > 
> >  >
> >  >By the way, if you really want to program via ZLIB, just use "gzopen" and
> >  >"gzread".  It is easy to do using these calls.
> > 
> > That would work if the files were in gzip format, but they aren't,
> zlib used to use gzip format but apparently it now uses the
> > deflate/inflate algorithms, so I don't think gzopen and
> > gzread will do it...
> > 
> > There are other routines in the zlib library to inflate
> > deflated data, it's just a matter of writing the program
> > to call them.
> > 
> > Am I way off base here?
> > 
> > Pete
> > 
> > 
> >  >
> >  >  Kevin W. Thomas
> >  >  Sun System Administrator & Meteorologist
> >  >  National Severe Storms Laboratory
> >  >  Norman, Oklahoma
> >  >
> >  >  Email:  address@hidden
> > 
> > 
> > --
> > +>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>+<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<+
> > ^ Pete Pokrandt                    V 1447  AOSS Bldg  1225 W Dayton St^
> > ^ Systems Programmer               V Madison,         WI     53706    ^
> > ^                                  V      address@hidden       ^
> > ^ Dept of Atmos & Oceanic Sciences V (608) 262-3086 (Phone/voicemail) ^
> > ^ University of Wisconsin-Madison  V       262-0166 (Fax)             ^
> > <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<+>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>+
> 

--------------------------------------------------------
 David Wojtowicz, Sr. Research Programmer/Systems Manager
 Department of Atmospheric Sciences Computer Services
 University of Illinois at Urbana-Champaign
 email: address@hidden  phone: (217)333-8390
--------------------------------------------------------