Here you are how to install libextractor 0.6.x on FreeBSD:
1. Make sure you have libtool updated to the version 2.2.6b (/usr/ports/devel/libtool22)
2. Then execute this command in the root of libextractor 0.6.x distribution:
CFLAGS="-I/usr/local/include" ./configure --with-ltdl-include=/usr/local/include \ --with-ltdl-lib=/usr/local/lib
3. Run make && make install as usual.