psql in the command line

Hi

I need some help regarding psql syntax.
I would like to copy text files into the database from the command line
in a script.
I have found already how can I do it as user postrgres:

test:/opt/pgsql# echo "copy test from '/data/log/bla';" | psql logdb
COPY

But when I try to execute it as root user I get the following error:

[est/data/log] su - postgres -c "echo 'copy test from /data/log/bla;'|
psql logdb"
ERROR: syntax error at or near "/" at character 16
LINE 1: copy test from /data/log/bla;

I have already tried with all kind of double and single quotes but it
does not work.
Anybody has an idea how can I make it run?

Thanks and regards
Aniko