To run the sample code you must have a php5 cli install along with the curl module enabled.
In a Debian-linux distro you can use the following commands to install the pre-requisites:

sudo apt-get update
sudo apt-get install php5-cli
sudo apt-get install php5-curl

You can execute the sample code by using the following commands in Linux:

php -f jsonrpc.php AppKey SessionToken
php -f rescript.php AppKey SessionToken