How was my running php compiled?

Question

I\'m trying to compile a new instance of PHP (5.4.0) from the source code and want to keep compatibility with the one (PHP 5.3.6-13ubuntu3.6) already installed from the dist

Answer 1

There should be a script php-config you can install on ubuntu to get the configure parameters used for php.

sudo apt-get install php5-dev
php-config  --configure-options

Answer 2

According to this bug report, the Configure Command output was intentionally suppressed from Ubuntu & Debian PHP builds.

Then recommend installing the source package via apt-get source php5:

If you want to see how PHP is built in Ubuntu, apt-get source php5, and peruse debian/rules, the ./configure output in phpinfo() is, as the changelog for the patch states, entirely misleading and not terribly informative.