The following lines should do the work :
$ cd libspctag-x.x
$ mdir build;cd build
$ cmake ..
# make install
This will build the project in the build subdirectory.
By default the install prefix is /usr/local. Use "cmake -DCMAKE_INSTALL_PREFIX=anywhere" to install in another directory.
You can choose build type using "cmake -DCMAKE_BUILD_TYPE=Debug|Release|RelWithDebInfo|MinSizeRel".
Compilation has only been tested with cmake 2.8.5 on Linux. I think it works with a 2.6, this is why cmake 2.6 is required in the CMakeList.txt. Tell me if it works with older versions.
If you can not or don't want use cmake, you can use following commands to compile and install libspctag
$ cd src
$ gcc -fPIC -Wall -c spctag.c
$ gcc -shared -Wl,-soname,libspctag.so.x -o libspctag.so.x.x spctag.o -lc
# cp libspctag.so.x.x /usr/local/lib
# cd /usr/local/lib
# ln -s libspctag.so.x.x libspctag.so.x
# ln -s libspctag.so.x libspctag.so