would like to list the netcdf-c version in the build summary, but how?

[edwardhartnett]

It would be great to add the netcdf-c version to the build summary in libnetcdff.settings. But how?

It's right here in netcdf_meta.h: #define NC_VERSION "4.8.0-development" But how do I get this value from the .h file into an autoconf shell variable? I don't know...

[WardF]

Let me double check but I have an idea for this.

[DennisHeimbigner]

You also can get that info from libnetcdf.settings if that is any easier.

[edwardhartnett]

Here's something I'm now doing in the PIO config to detect version 4.7.2, which won't work. One could imagine doing this for every version, and so learning the version in configure:

# Is this version 4.7.2, which does not work?
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include "netcdf_meta.h"],
[[#if NC_VERSION_MAJOR == 4 && NC_VERSION_MINOR == 7 && NC_VERSION_PATCH == 2
# error
#endif]
])], [have_472=no], [have_472=yes])
AC_MSG_CHECKING([whether this is netcdf-c-4.7.2])
AC_MSG_RESULT([${have_472}])
if test "x$have_472" = xyes; then
   AC_MSG_ERROR([PIO cannot build with netcdf-c-4.7.2, please upgrade your netCDF version.])
fi

 The CMake version is:

###
# Check to see if this is netcdf-c-4.7.2, which won't work.
###
CHECK_C_SOURCE_COMPILES("
#include <netcdf_meta.h>
#if NC_VERSION_MAJOR == 4 && NC_VERSION_MINOR == 7 && NC_VERSION_PATCH == 2
#else
      choke me
#endif
int main() {return 0;}" HAVE_472)
if (HAVE_472)
  message (FATAL_ERROR "PIO cannot build with netcdf-c-4.7.2, please upgrade your netCDF library")
endif ()

[WardF]

Just turning back to this and what you've suggested is very much in line with what I was thinking, although in cmake at least it can be turned into a utility macro in expectation we'll want to keep using this down the line for other versions as well.

[DennisHeimbigner]

A couple of other approaches:

1. for CMake, use CMake string operations to extract some pattern from libnetcdf.settings
2. for automake create a shell script that does the same thing as #1 e.g. findsetting.sh "NetCDF Version" ${NCDIR}/libnetcdf.settings where NCDIR is the root dir for the netcdf-c installation or build directory