Using PHP for search and replace

Hello all, Currently, both Mandrake and RedHat use the following trick: perl -pi -e "s|^;extension=mysql.so|extension=mysql.so|" /etc/php.ini This sucks, because you then need perl to install a PHP extension. We sure could use sed, but this requires a temporary file, and this creates some security risks. Is there a quick and easy way to do this kind of thing in PHP? Or would this be something that we could integrate? And I know there's a new solution with the new config-file-scan-dir, but my question is a general search-and-replace solution. Any thoughts? Jean-Michel