problems with copy command

hello everybody,
I tried to copy a file into a table from the postgres terminal, and all
worked fine.
But when I tryed the same with the php pg_exec() command the result was:

PostgresSQL query failed: ERROR: You must have Postgres superuser privilege
to do a COPY directly to or from a file. Anyone can COPY to stdout or from
stdin. Psql's \copy command also works for anyone.

I can't use \copy from php because there is no \copy interface in php, only
pg_exec(sql command), so the only way is to use stdin!
Someone has ideas about how to pipe the file and than read the pipe from the
copy sql command?

hope will interest
bye