To add, delete, or change metadata or data in a binary netCDF file:

 

 

• Use ncdump to convert netCDF file to CDL
• Use a text editor to make desired change to CDL
• Use ncgen to turn modified CDL back into modified netCDF file
• This is not very practical for large netCDF files.

To create a new netCDF file with lots of metadata:

 

 

• Use a text editor to write a CDL file with lots of metadata but little or no data.
• Use ncgen to generate a C or Fortran program that writes the corresponding binary netCDF file.
• Insert easy "var_put"calls to the netCDF library for the data writing part of the task.
• Compile and run the program to create the netCDF file
• Use ncdump to verify the desired file is created.

To convert a small classic netCDF file into an equivalent netCDF-4 classic model file:

 

 

  $ ncdump small.nc > tmp.cdl
  $ ncgen -o small4.nc -k 4 tmp.cdl

2009 Unidata NetCDF Workshop for Developers and Data Providers > NetCDF Utilities: ncdump and ncgen