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Re: xdrstdio.c routines

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  • Subject: Re: xdrstdio.c routines
  • Date: Thu, 05 May 1994 16:18:35 -0600
> Organization: GM R@D Center
> Keywords: 199405051259.AA16838

Hi Dick,

> I have been building NetCDF access system to run under MSDOS and
> ultimately windows, maybe as a DLL.
> 
> I am early on in this project.  Have XDRTEST working.  Am trying to get
> CDFTEST to function, and having some problems.
> 
> Have noticed two versions of xdrstdio.c, one in the XDR directory and
> another located in the libsrc directory.
> 
> The version of xdrstdio.c in the libsrc directory has a non conditional
> include of unistd.h -- I am not sure of how that relates to DOS
> implementation.
> 
> I may be way off base, or be lacking some information.
> 
> Could you point me to the information source or person who could steer me
> in the right direction.

The netCDF library was originally layered on top of the stdio library with
calls to the functions in xdr/xdrstdio.c, but we later added some
netCDF-specific optimizations, creating libsrc/xdrstdio.c to replace
xdr/xdrstdio.c.

Then we came up with an implementation of this layer that did not use stdio,
but instead used the POSIX read() and write() calls and did its own
buffereing, resulting in further performance enhancements over the version
based on the stdio library.  This last implementation is in
libsrc/xdrposix.c, and is used by default instead of libsrc/xdrstdio.c to
link against.  The reason we kept all three files in the distribution was
for help in porting to new platforms, such as you are doing.

Probably a good way to port to your environment is to ignore the two
versions of xdrstdio.c and start with xdrposix.c instead.  Replace the POSIX
I/O calls with I/O calls specific to your platform.

__________________________________________________________________________
                      
Russ Rew                                              UCAR Unidata Program
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