We're running a hundred or so legacy PHP websites on an older server which runs Gentoo Linux. When these sites were built latin1 was still the common charset, both in PHP and MySQL.

To make sure those older sites used latin1 by default, while still allowing newer sites to use utf8 (our current standard), we set the default connect charset in php.ini:

mysql.connect_charset = latin1
mysqli.connect_charset = latin1
pdo_mysql.connect_charset = latin1

Specific more modern sites could override this in their bootstrapping code with:

<?php
mysql_set_charset("utf8", $dsn );

...and all was well.

Now the server is overloaded and we're no longer with that hoster, so we're moving all these sites to a faster server at our standard hoster, which uses RHEL 5 as their OS of choice.

In setting up this new server I discover to my surprise that the *.connect_charset directives are a Gentoo specific patch to PHP, and RHEL's version of PHP doesn't recognize them! Now how do I set PHP to connect to MySQL with the latin1 charset?

I thought about setting a default in my.cnf but would prefer not to force every app and client to default to latin1. Our policy is to use utf8, and we'd like to restrict the exception to PHP only. Also, converting every legacy site to properly use utf8 is not doable since many are of the touch 'm and you break 'm kind. We simply don't have the time to go fix them all.

How would I set a default mysql/mysqli/pdo_mysql connection charset to latin1 for PHP, while still allowing individual scripts to override this to utf8 with mysql_set_charset()?