[netCDF #CPW-270700]: compile error

Bin,

> Thanks for the quickly response. The DEM files are at 
> ftp://landsc1.nascom.nasa.gov/outgoing/c6_dem/sin_1km/  You can download any 
> HDF file over there to test.
> Actually, I can use ncdump to open the file header without any problem. 
> However, nc_open is not working....

OK, thanks, when I use ncdump -sh on one of the files, I get a segmentation
violation trying to access chunk sizes, due to a bug in nc_inq_chunking() when
reading HDF4 files like these DEM files.  We're working on a fix, and have a
created an issue for the problem:

  https://bugtracking.unidata.ucar.edu/browse/NCF-272

--Russ

> -----Original Message-----
> From: Unidata netCDF Support [mailto:address@hidden]
> Sent: Friday, May 30, 2014 11:52 AM
> To: Tan, Bin (GSFC-619.0)[SIGMA SPACE CORPORATION]
> Cc: address@hidden
> Subject: [netCDF #CPW-270700]: compile error
> 
> Bin,
> 
> > Thanks Russ! I finally got the netcdf library successfully built and 
> > installed.
> > However, I met another problem when using the libraries. I tried to open 
> > HDF4 data in a C program with the following lines:
> >
> > retval = nc_open("DEM_SN_H.h32v07.006_0.hdf", NC_NOWRITE, &ncid);
> > ERR(retval);
> >
> > I always got segmentation fault on this line.
> >
> > Should I use nc_open to open HDF4 files?
> 
> Your nc_open call is correct for HDF4 files.  And the netCDF library should 
> not get a segmentation fault when it can't read an HDF4 file.
> It's been reported as a bug that some netCDF library functions fail on HDF4 
> file inquiries for compression or chunking parameters, but I haven't seen any 
> reports of a segmentation fault on just calling nc_open on an HDF4 file.
> 
> You should be able to use netCDF-4 on HDF4 SD (Scientific Data) files.
> The netCDF library calls the HDF4 library underneath, so you have to build 
> netCDF so that it knows where the HDF4 library is installed:
> 
> http://www.unidata.ucar.edu/netcdf/docs/getting_and_building_netcdf.html#build_hdf4
> 
> If you've done this and it still fails, and you know the file you're trying 
> to open is an HDF4 SD file, please make the file available to us so we can 
> try to reproduce the problem here.
> 
> Thanks.
> 
> --Russ
> 
> > -----Original Message-----
> > From: Unidata netCDF Support [mailto:address@hidden]
> > Sent: Thursday, May 29, 2014 10:54 PM
> > To: Tan, Bin (GSFC-619.0)[SIGMA SPACE CORPORATION]
> > Cc: address@hidden
> > Subject: [netCDF #CPW-270700]: compile error
> >
> > Bin,
> >
> > > However, the program still compiled with old HDF5 libraries. Do you have 
> > > any idea what else I should revise?
> >
> > It might also be helpful to try these instructions that get output when you 
> > successfully install the netCDF libraries:
> >
> > If you ever happen to want to link against installed libraries in a
> > given directory, LIBDIR, you must either use libtool, and specify the
> > full pathname of the library, or use the `-LLIBDIR' flag during
> > linking and do at least one of the following:
> >
> > - add LIBDIR to the `LD_LIBRARY_PATH' environment variable during
> > execution
> > - add LIBDIR to the `LD_RUN_PATH' environment variable during linking
> > - use the `-Wl,-rpath -Wl,LIBDIR' linker flag
> > - have your system administrator add LIBDIR to `/etc/ld.so.conf'
> >
> > See any operating system documentation about shared libraries for more
> > information, such as the ld(1) and ld.so(8) manual pages.
> >
> > --Russ
> >
> > Russ Rew                                         UCAR Unidata Program
> > address@hidden                      http://www.unidata.ucar.edu
> >
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: CPW-270700
> > Department: Support netCDF
> > Priority: Normal
> > Status: Closed
> >
> >
> Russ Rew                                         UCAR Unidata Program
> address@hidden                      http://www.unidata.ucar.edu
> 
> 
> 
> Ticket Details
> ===================
> Ticket ID: CPW-270700
> Department: Support netCDF
> Priority: Normal
> Status: Closed
> 
> 
> Hi, Russ
> 
> Thanks for the quickly response. The DEM files are at 
> ftp://landsc1.nascom.nasa.gov/outgoing/c6_dem/sin_1km/  You can download any 
> HDF file over there to test.
> Actually, I can use ncdump to open the file header without any problem. 
> However, nc_open is not working....
> 
> Bin
> 
> -----Original Message-----
> From: Unidata netCDF Support [mailto:address@hidden]
> Sent: Friday, May 30, 2014 11:52 AM
> To: Tan, Bin (GSFC-619.0)[SIGMA SPACE CORPORATION]
> Cc: address@hidden
> Subject: [netCDF #CPW-270700]: compile error
> 
> Bin,
> 
> > Thanks Russ! I finally got the netcdf library successfully built and 
> > installed.
> > However, I met another problem when using the libraries. I tried to open 
> > HDF4 data in a C program with the following lines:
> >
> > retval = nc_open("DEM_SN_H.h32v07.006_0.hdf", NC_NOWRITE, &ncid);
> > ERR(retval);
> >
> > I always got segmentation fault on this line.
> >
> > Should I use nc_open to open HDF4 files?
> 
> Your nc_open call is correct for HDF4 files.  And the netCDF library should 
> not get a segmentation fault when it can't read an HDF4 file.
> It's been reported as a bug that some netCDF library functions fail on HDF4 
> file inquiries for compression or chunking parameters, but I haven't seen any 
> reports of a segmentation fault on just calling nc_open on an HDF4 file.
> 
> You should be able to use netCDF-4 on HDF4 SD (Scientific Data) files.
> The netCDF library calls the HDF4 library underneath, so you have to build 
> netCDF so that it knows where the HDF4 library is installed:
> 
> http://www.unidata.ucar.edu/netcdf/docs/getting_and_building_netcdf.html#build_hdf4
> 
> If you've done this and it still fails, and you know the file you're trying 
> to open is an HDF4 SD file, please make the file available to us so we can 
> try to reproduce the problem here.
> 
> Thanks.
> 
> --Russ
> 
> > -----Original Message-----
> > From: Unidata netCDF Support [mailto:address@hidden]
> > Sent: Thursday, May 29, 2014 10:54 PM
> > To: Tan, Bin (GSFC-619.0)[SIGMA SPACE CORPORATION]
> > Cc: address@hidden
> > Subject: [netCDF #CPW-270700]: compile error
> >
> > Bin,
> >
> > > However, the program still compiled with old HDF5 libraries. Do you have 
> > > any idea what else I should revise?
> >
> > It might also be helpful to try these instructions that get output when you 
> > successfully install the netCDF libraries:
> >
> > If you ever happen to want to link against installed libraries in a
> > given directory, LIBDIR, you must either use libtool, and specify the
> > full pathname of the library, or use the `-LLIBDIR' flag during
> > linking and do at least one of the following:
> >
> > - add LIBDIR to the `LD_LIBRARY_PATH' environment variable during
> > execution
> > - add LIBDIR to the `LD_RUN_PATH' environment variable during linking
> > - use the `-Wl,-rpath -Wl,LIBDIR' linker flag
> > - have your system administrator add LIBDIR to `/etc/ld.so.conf'
> >
> > See any operating system documentation about shared libraries for more
> > information, such as the ld(1) and ld.so(8) manual pages.
> >
> > --Russ
> >
> > Russ Rew                                         UCAR Unidata Program
> > address@hidden                      http://www.unidata.ucar.edu
> >
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: CPW-270700
> > Department: Support netCDF
> > Priority: Normal
> > Status: Closed
> >
> >
> Russ Rew                                         UCAR Unidata Program
> address@hidden                      http://www.unidata.ucar.edu
> 
> 
> 
> Ticket Details
> ===================
> Ticket ID: CPW-270700
> Department: Support netCDF
> Priority: Normal
> Status: Closed
> 
> 
Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: CPW-270700
Department: Support netCDF
Priority: Normal
Status: Closed