PECL is a repository for PHP extensions. It’s where old extensions go to die and new extensions are developed. In a previous post I gave the commands to install PDO from PECL but forgot to mention that before you can install anything from PECL you need to install the php5-dev package first.

% sudo apt-get install php5-dev

You need to install the dev package because PECL extensions are compiled into PHP. This should tell you two important things:

  1. Be very careful when deciding which extensions to include. While an unstable PEAR package might cause your application to fail a bad PECL extension can cause your web server to crash.
  2. When you upgrade PHP you will probably need to reinstall the PECL extension.