standard_conforming_strings and pg_escape_string()

Hi.

I'm using PostgreSQL 8.3 with PHP's "pgsql" module (libpq 8.3.7). When
the server's standard_conforming_strings setting is off (this is
currently still the default, I believe), I use something like this to
escape strings:

if ($escWildcards) {
$str = strtr($str, array("%" => '\%', "_" => '\_'));
}
return "E'" . pg_escape_string($str) . "'";

I would like our database abstraction to be able to handle both settings
for standard_conforming_strings transparently, i.e. perform the escaping
according to the current DB server settings. Since pg_escape_string() is
aware of the current database connection, I had expected its behavior to
change accordingly:

no std strings:
x\y --> x\\y
with std strings:
x\y --> x\y

Unfortunately, this doesn't happen. Isn't pg_escape_string() the
preferred way to escape strings for PostgreSQL in PHP?

And finally, would it be safe to always use the E'\\' syntax, regardless
of how standard_conforming_strings is set on the server?

- Conrad