How to run Workflow Background Process from SQL*Plus? And from Unix?

How to run Workflow Background Process from SQL*Plus?

BEGIN
  wf_engine.background (itemtype=>NULL ,
                        process_deferred=>TRUE ,
                        minthreshold=>NULL ,
                        maxthreshold=>NULL ,
                        process_timeout=>FALSE ,
                        process_stuck=>FALSE);
END;

How to run Workflow Background Process from Unix?

$ $FND_TOP/Admin/Sql/wfbkg.sql