Install PHP PECL on CentOS-
When trying to install the PECL timezonedb module onto one of my webservers the other day, I discovered that the PECL library was not installed. (PECL is a repository for PHP extensions). I did a Google search for how to install PECL but couldn't find anything to help. In the end I managed to work out that by installing PEAR, PECL is installed as well.
On a CentOS, Red Hat Enterprise Linux or Fedora machine and their derivitives, this is a simple as running this command, either using sudo or as the root user:
yum install php-pear
The pecl command can then be found at /usr/bin/pecl
On other Linux distributions it should be a similar process.