After some discussions about what could be useful since psql scripts now accepts tests, this patch sets a few variables which can be used by psql after a "front door" (i.e. actually typed by the user) query:
- RESULT_STATUS: the status of the query - ERROR: whether the query failed - ERROR_MESSAGE: ... - ROW_COUNT: #rows affected
SELECT * FROM ; \if :ERROR \echo oops \q \endif
I'm not sure that the names are right. Maybe STATUS would be better than RESULT_STATUS.
