Capturing all output from psql into a file

Hi,

I am doing this mass table creation (approx 600 tables) and then
mass dump of records into these tables (~900megs of flat files).

All the table creation and record copy is being done from a file
using \i sqlscript.txt.

How can I capture all the output which comes out from psql. I need
all the errors and not just the query result.

I have tried to use \o file.txt and \g file.txt but they only
seem to output the query result.

Many thanks.

Huy