cdkbook

FindAllRings.groovy

Source code:

@Grab(group='org.openscience.cdk', module='cdk-bundle', version='2.9')

import org.openscience.cdk.interfaces.*;
import org.openscience.cdk.io.*;
import org.openscience.cdk.ringsearch.*;
import org.openscience.cdk.io.IChemObjectReader.Mode;
import org.openscience.cdk.*;
import java.io.File;

reader = new MDLV2000Reader(
  new File("data/azulene.mol").newReader(),
  Mode.STRICT
);
azulene = reader.read(new AtomContainer());
ringset = new AllRingsFinder().findAllRings(azulene)
println "Number of rings: $ringset.atomContainerCount"

Output:

Number of rings: 3