The script automates the installation or updating of an existing phpstorm installation on a unix machine (tested on Debian Linux 6 and 7).
The script itself is very verbose. If something happens, it should support you. Furthermore, the script is creating a backup of your existing installation and outputs the backup path.
First of all, go to the download page and download the newest version.
# simple install or update
php phpstorm.php path/to/linux/php/version.tar.gz
# install or update and change group
# good if you created a "developer" group on your system
php phpstorm.php path/to/linux/php/version.tar.gz your_group_name