如何从Ant中获取当前PID？

 <property environment="env"/>
 <target name="show-pid">
    <echo>Current PID: ${os.pid}</echo>
  </target>
</project>

 <target name="show-pid">
   <script language="javascript">
      <![CDATA[
        var pid = java.lang.ProcessHandle.current().pid();
        println("Current PID: " + pid);
      ]]>
    </script>
  </target>
</project>

 <target name="show-pid">
   <script language="groovy">
      <![CDATA[
        def pid = org.apache.tools.ant.util.JavaEnvUtils.getAvailableProcessors();
        println("Current PID: " + pid);
      ]]>
    </script>
  </target>
</project>