PHP 5.2 brings lots of little useful features and CentOS 5.3 comes with PHP 5.1. So most of my PHP apps failed. The easiest way to solve this is to :

  • Edit /etc/yum.repos.d/CentOS-Testing.repo and put this:

    [c5-testing]
    name=CentOS-5 Testing
    baseurl=http://dev.centos.org/centos/5/testing/$basearch/
    enabled=1
    gpgcheck=1
    gpgkey=http://dev.centos.org/centos/RPM-GPG-KEY-CentOS-testing
    
  • Launch:

    yum update php
    

Source : Fresh Blurbs