prefix=/usr/pkg
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Name: libarchive
Description: library that can create and read several streaming archive formats
Version: 3.4.3
Cflags: -I${includedir}
Cflags.private: -DLIBARCHIVE_STATIC
Libs: -L${libdir} -larchive
Libs.private: -llzma -lbz2 -lz 
