Question

Could someone advise on how to enable the json_encode function in PHP?

I have a clean install of Centos 5.6 and have just installed Virtualmin.

Does anyone know the next steps to take?

Answer 1

As in http://www.php.net/manual/en/json.requirements.php

Requirements

There is no installation needed to use these functions; they are part of the PHP core.

Just PHP >= 5.2.0

Edit: saw in a comment also this

On RHEL5/CentOS5 add the EPEL repository (http://fedoraproject.org/wiki/EPEL).

After that, installation is as simple as:

sudo yum install php-pecl-json

Don’t know if this apply for your question, I don’t have a Centos server…

For Ubuntu:

sudo aptitude install php5-json