Set up Dotdeb
First add Dotdeb to your Apt sources:
sudo vim /etc/apt/sources.list
/etc/apt/sources.list
deb http://packages.dotdeb.org squeeze all
deb-src http://packages.dotdeb.org squeeze all
deb http://packages.dotdeb.org squeeze-php54 all
deb-src http://packages.dotdeb.org squeeze-php54 all
Save & Exit. Now go for the next-
curl http://www.dotdeb.org/dotdeb.gpg | sudo apt-key add -sudo apt-get update
Now Install PHP 5.4
sudo apt-get dist-upgrade
Test it-
php -v
I found there were a couple of warning messages – I had to remove the old Suhosin & APC configuration files, and manually re-install APC:
sudo rm /etc/php5/conf.d/suhosin.ini
sudo rm /etc/php5/conf.d/apc.ini
sudo apt-get install php5-apc
Optionally install MySQL 5.5
If you get this message:
The following packages have been kept back:
mysql-server
It’s probably because Dotdeb includes MySQL 5.5 and Squeeze includes MySQL 5.1. You can choose to upgrade with this command:
sudo apt-get install mysql-server
You may find phpMyAdmin gives a warning like this:
Your PHP MySQL library version 5.1.66 differs from your MySQL server version 5.5.30. This may cause unpredictable behavior.
You can fix this by installing the new MySQL Native Driver extension:
sudo apt-get install php5-mysqlnd