Oracle - How to generate script from sql developer

Question

How to take script for schema of the tables, stored procedures of Oracle through SQL Developer tool (SQLPLUS command line interface)?

Answer 1

The basic answer appears to be 'use the dbms_metadata package'. The axuilliary question is:

But what if I want to generate a script for all the tables at a time?

And the answer, presumably, is to interrogate the system catalog for the names and owners of all the tables:

SELECT dbms_metadata.get_ddl('TABLE', s.tabname, s.tabowner)
  FROM system_catalog_describing_tables AS s
 WHERE ...any conditions that are needed...

I'm not sufficiently familiar with Oracle to know the system catalog. In Informix, which I do know, assuming that there was a procedure dbms_metadata.get_ddl, the query would be:

SELECT dbms_metadata.get_ddl('TABLE', s.tabname, s.owner)
  FROM "informix".systables AS s
 WHERE tabid >= 100 AND tabtype = 'T';

In Informix, tabids less than 100 are reserved for the system catalog, and non-tables (views, synonyms, sequences and a few other esoteric things) are excluded by requiring the right 'tabtype'.