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2.6 Open a NetCDF Dataset for Access: nc_open

The function nc_open opens an existing netCDF dataset for access.

Usage

     int nc_open (const char *path, int omode, int *ncidp);
path
File name for netCDF dataset to be opened.
omode
A zero value (or NC_NOWRITE) specifies the default behavior: open the dataset with read-only access, buffering and caching accesses for efficiency

Otherwise, the creation mode is NC_WRITE, NC_SHARE, or NC_WRITE|NC_SHARE. Setting the NC_WRITE flag opens the dataset with read-write access. ("Writing" means any kind of change to the dataset, including appending or changing data, adding or renaming dimensions, variables, and attributes, or deleting attributes.) The NC_SHARE flag is appropriate when one process may be writing the dataset and one or more other processes reading the dataset concurrently; it means that dataset accesses are not buffered and caching is limited. Since the buffering scheme is optimized for sequential access, programs that do not access data sequentially may see some performance improvement by setting the NC_SHARE flag.

ncidp
Pointer to location where returned netCDF ID is to be stored.

Errors

nc_open returns the value NC_NOERR if no errors occurred. Otherwise, the returned status indicates an error. Possible causes of errors include:

Example

Here is an example using nc_open to open an existing netCDF dataset named foo.nc for read-only, non-shared access:

     #include <netcdf.h>
        ...
     int status;
     int ncid;
        ...
     status = nc_open("foo.nc", 0, &ncid);
     if (status != NC_NOERR) handle_error(status);