[Proj] value of PROJ_LIB variable

[Hamish]

> A default build on Unix-like systems will define the PROJ_LIB macro to
> be the default install directory in pj_open_lib.c.  This is often
> /usr/local/share/proj.
> 
> You can also use the pj_set_finder() and pj_set_searchpath() functions
> programatically to override how the files are found.


Is there a way to figure out what this has been set to after the binary
is made? e.g. something analogous to gdal-config.

In GRASS we'd like to auto-locate & parse the EPSG file for quickly
defining new projects from the startup screen if given a valid code.
Usually libproj is found in the LD search path so our ./configure
hasn't been told where to look. Knowing --prefix would be enough I
think, but PROJ_LIB is the path we want to know.

?

thanks,
Hamish