pkgconfig enables a high level of integration with minimal effort. There is no more needs to handle hosts of possible NUT installation path in your configure script !

To check if NUT is available, use:

$ pkg-config --exists libupsclient --silence-errors

To get CFLAGS, use:

$ pkg-config --cflags libupsclient

To get LD_FLAGS, use:

$ pkg-config --libs libupsclient

pkgconfig support (.pc) files are provided in the present directory of the source distribution (nut-X.Y.Z/lib/), and installed in the suitable system directory if you have enabled --with-dev.

The default installation directory ("/usr/lib/pkgconfig/") can be changed with the following command:

./configure --with-pkgconfig-dir=PATH

You can also use this if you are sure that pkg-config is installed:

PKG_CHECK_MODULES(LIBUPSCLI, libupsclient >= 2.4.0)
PKG_CHECK_MODULES(LIBNUTSCAN, libnutscan >= 2.6.2)