Re: 961108: netcdf I/O question

>To: address@hidden
>From: Jim Barbour <address@hidden>
>Subject: netcdf I/O question
>Organization: NOAA/FSL
>Keywords: 199611081713.AA09064

Hi Jim,

> I am trying to get a sense of how NetCDF's I/O works.
> 
> o Does is use stdio or unix I/O (open, read, write, etc.)

It uses POSIX I/O, which is the standardized name for Unix I/O, except
that it's supported on non-Unix systems: open, read, write, lseek, ...

> o Does it typically do large os small reads?

It tries to buffer I/O somewhat, by determining a preferred I/O block
size.  If a preferred block size isn't available, it just uses 8192 byte
buffers.

For more details, see the file netcdf/src/libsrc/posixio.c in the
distribution of the C-language-only alpha release at

    ftp://ftp.unidata.ucar.edu/pub/netcdf/netcdf-3.1a.tar.Z

--Russ

_____________________________________________________________________

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