Viewing definition of an object using DBMS_METADATA

set long 50000
set pagesiz 50

select dbms_metadata.get_ddl('PACKAGE', 'ZPB_BUILD_METADATA', 'APPS') from dual;
select dbms_metadata.get_ddl('PACKAGE_BODY', 'ZPB_BUILD_METADATA', 'APPS') from dual;

also using

select text from dba_source where name='' and owner='';