berkeley db env vars

Some influential environment variables:
CC C compiler command
CFLAGS C compiler flags
LDFLAGS linker flags, e.g. -L if you have libraries in a
nonstandard directory
LIBS libraries to pass to the linker, e.g. -l
CPPFLAGS C/C++/Objective C preprocessor flags, e.g. -I if
you have headers in a nonstandard directory
CXX C++ compiler command
CXXFLAGS C++ compiler flags
CXXCPP C++ preprocessor
CPP C preprocessor
F77 Fortran 77 compiler command
FFLAGS Fortran 77 compiler flags