1. Start psql with the database that you'd like to export from...
$ psql [DATABASE]
2. Toggle the output mode to unaligned (\a toggles between unaligned and aligned output mode)
=# \a
3. Turn "tuples only" off (\t toggles between tuples on and off)
=# \t
4. Set the output file (replace [FILE] with what you'd like to call your output file). It will send all query results to the file or |pipe.
=# \o [FILE]
5. Run whatever query you'd like to send to the output file. For example,
=# SELECT * FROM [TABLE];
In summary:
\a
\t
\o /tmp/outputfile.txt
SELECT ......
\o
