[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Problem handling NULL bytes in TDS

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: Re: Problem handling NULL bytes in TDS
  • Date: Thu, 24 Apr 2008 10:29:08 -0600
Weve decided that we should indeed truncate any Strings if they contain a null byte. I will put that fix into both the 2.22 branch and the trunk. Kevin, do you need this fix right away? 

Kevin O'Brien wrote:

Hi John -
It is indeed a netcdf file, albeit with messed up attributes. You can download the file at http://nomads.gfdl.noaa.gov/dods-data/gfdl_cm2_1/CM2.1U-D4_1860-2000-AllForc_H1/pp/ice_tripolar/ts/monthly/vsi_O1.186101-200012.nc
I could send you the header, but I'm not sure how the NULL bytes would get translated along the way...But let me know if you want that or if it's just easier to download the file. I think it's about 500Mbytes... 

kev

John Caron wrote:

Hi Kevin:
Theres some question about whether this is the right thing to do or not. Is this a netcdf file? If so, can you send it to me? 

Kevin O'Brien wrote:

Hi John -
I ran across what looks to potentially be a bug in the way TDS handles NULL bytes within attributes. If you plug this URL into the netCDF Java tools interface: 
     http://data1.gfdl.noaa.gov:8380/thredds/dodsC/test_vsi_monthly
And hit the ncdump tab, and then scroll down to the VSI variable, you'll see the null bytes in the 
   cell_methods
and
   coordinates
attributes. I was talking to Roland about this, and he seems to think that the attribute value should end w/ the NULL byte. Also, if you then hit the "NcML" tab, you'll get an error complaining about the NULL byte, though in a different attribute (grid_version in this case). 

If there's any more information I can provide, please let me know..

thanks-
Kevin