# Start copying some data to PostgeSQL. Here, STDIN is relative to the
# script. So the PostgreSQL STDIN being mentioned is actually just the
# stuff being written over $dbh->func( ..., 'putline');
$dbh->func( 'COPY some_table FROM STDIN', 'putline' );

# Write whatever was read from $fh to PostgreSQL's COPY.
while ( <$fh> )
{
    chomp;
    $dbh->func( $_, 'putline' );
}

# Tell PostgreSQL that the COPY is over with.
$dbh->func( "\\.\n", 'putline' );