How to exit from PostgreSQL command line utility: psql
Type \q and then press ENTER to quit psql.
UPDATE: 19-OCT-2018
As of PostgreSQL 11, the keywords "quit" and "exit" in the PostgreSQL command-line interface have been included to help make it easier to leave the command-line tool.
My usual key sequence is:
quit()quitexit()exitqq()!q^ChelpAlt + Tabgoogle.comQuit PSQL\qI think veterans of the psql command line usually shorten that to just:
\q