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From: Ivan Shmakov on 15 Apr 2010 10:57
>>>>> Brendan <brendandetracey(a)yahoo.com> writes:
>>>>> Ivan Shmakov <i...(a)main.uusia.org> wrote:

[...]

>> BTW, speaking of the HDF-EOS files, is there a way to extract
>> metadata, more straightforward than, say, the Shell functions below?
>> (Converting the metadata to XML may be the way, but the conversion
>> software I've found is apparently non-free, Java-based, and failed
>> to process the files we've tried it on.)

>> $ file=ladsweb.nascom.nasa.gov/allData/5/MOD08_M3/2010/032/MOD08_M3.A2010032.�005.2010062234836.hdf
>> $ hdfeos_metadata_get_quoted_scalar "$file" RANGEBEGINNINGDATE
>> 2010-02-01
>> $ hdfeos_metadata_get_quoted_scalar "$file" RANGEENDINGDATE
>> 2010-03-01
>> $

[...]

> I can't give a definite answer because I use Matlab to read hdf. I
> don't know much about hdf4 format. If the bytes you seek are always
> in the same position in the file I would use bash command "od" to
> extract.

The HDF-EOS format is, basically, a convention of using specific
global attributes to hold certain metadata items. The metadata
is represented using (an) Object Description Language (ODL),
like:

$ ncget-hdf -T "$file" :CoreMetadata.0

GROUP = INVENTORYMETADATA
GROUPTYPE = MASTERGROUP

GROUP = ECSDATAGRANULE

OBJECT = LOCALGRANULEID
NUM_VAL = 1
VALUE = "MOD08_M3.A2010032.005.2010062234836.hdf"
END_OBJECT = LOCALGRANULEID

[...]

END_GROUP = ECSDATAGRANULE

[...]

END_GROUP = INVENTORYMETADATA

END
$

As one could see, it's not a trivial thing to parse. (Luckily,
as present in the most files I've seen, certain extra conditions
are met, so I could simplify the parsing down to the ways easily
implementable using Sed.)

> Otherwise gdal tool gdalinfo might do the trick.

Well, indeed, it does. Though I'd prefer a more light-weight
solution.

> Can install from scratch or grab an FWTools build.

# apt-get install gdal-bin

does it for me.

> Good Luck!

--
FSF associate member #7257
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