Re: 19980730: ncdf_close

>To: address@hidden
>From: "R. Bauer" <address@hidden>
>Subject: ncdf_close
>Organization: Forschungszentrum Juelich Gmbh (KFA)
>Keywords: 199807301105.FAA22051

Hi Reimar,

> I have a problem with different file systems and netCDF 2.4 build in to
> idl.
> I know and I have already 3.4 too but not for idl.
> 
> First I will show the syntax I used.
> 
> 
>          file_id = NCDF_OPEN(new_file,/nowrite)
>          .
>          .
>          NCDF_CLOSE,file_id
> 
> 
>          file_id = NCDF_OPEN(new_file,/write)
>           .
>           .
>          NCDF_CONTROL,file_id,/redef
> 
> 
> Sometimes If we used a PC NOVELL based fileserver it hangs in the /redef
> line and says that's it could not enter redef mode. The same source and
> data on a NT File Server or UNIX Filesystems or the local disc gaves no
> problem.
> 
> I believe that's in some cases the NCDF_CLOSE wasn't finished totally
> before the NCDF_OPEN  is reached.
> How can I get an information about the status of CLOSE?

We don't have the source for the IDL interface to netCDF, but I assume
that NCDF_CLOSE just calls the C function 

   int ncclose(int file_id)

which returns -1 in case of error and 0 otherwise.  It doesn't appear to
be possible to get the status of the ncclose() call when using the IDL
NCDF_CLOSE statement, but that question should probably be directed to the
technical support group for IDL at

   address@hidden 

Checking the source for ncclose() in version 2.4, an error can occur in
closing a read-only file only if the file_id was not a valid ID for an
open netCDF file.

We don't know anything about what can happen when closing a file opened
on a PC NOVELL based fileserver.  This might be a problem to contact
Novell about.

> Is this a problem wich is fixed in later versions?

I don't think there are any changes in later versions that would be
relevant to this problem.  Sorry we can't be of more help ...

--Russ

_____________________________________________________________________

Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu