Re: [netcdfgroup] Closing files opened only for reading (C interface - nc_close()?)

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: Re: [netcdfgroup] Closing files opened only for reading (C interface - nc_close()?)
• From: Paul Ganssle <p.g.anssle@xxxxxxxxx>
• Date: Mon, 1 Aug 2011 16:32:16 -0700

In preparing to paste a code snippet, I found that this *only* happens if I
include a string in the file.  Here is a test function that I made, as well
as an example of how I'm calling nc_open and nc_close:
http://pastebin.com/63HbAWSy

If I comment out either method of putting the string in there, the same
thing happens, unless I comment out both methods. Variables, arrays and
groups don't cause the issue.

Here's a raw paste if you don't want to look at pastebin:

// Test function testing strings.
int rv, ncid;
if(rv = nc_create(fname, NC_NETCDF4, &ncid))
goto error; // Error opening file.

char *string = malloc(250);
sprintf(string, "This is a string.");
 nc_put_att_string(ncid, NC_GLOBAL, "string1", 1, &string);
 char *string2 = "This is also a string";
nc_put_att_string(ncid, NC_GLOBAL, "string2", 1, &string2);
 free(string);
nc_close(ncid);
return rv;

/******* nc_open call: ********/
// Open the netCDF file.
if(rv = nc_open(fname, NC_NOWRITE, &ncid))
goto error;

/******* nc_close call: ********/
if(ncid >= 0)
     nc_close(ncid);

Note that I can actually read those strings or variables and attributes
which are arrays of strings just fine. The only thing that causes problems
is the nc_close(ncid) call, which suspends execution/crashes the program if
there's a string in the file for some reason.

Now that I know this, it's not such a horrible thing, since I can just store
those as arrays of chars, but the string type is actually pretty convenient,
so if anyone has suggestions as to how I can make it deal with the fact that
strings exist, please let me know.

      -Paul

• Follow-Ups:
  • Re: [netcdfgroup] Closing files opened only for reading (C interface - nc_close()?)
    • From: David William Pierce