According to here, to set security for xampp, you can run the following commands:
to all questions and create a password for each of the categories.
When you are finished, don't forget to type:
Now, on the index.php page it should ask you for a username. The default username is
Use the password you created for the password.
It is not recommended you give permission to john instead of root for security purposes. That is one of the many reasons viruses are so easily to install on a windows system because you don't need root permission to install applications. Many applications install to the opt directory.
If there is something you want to do to files in that directory, John can use the sudo command to alter those files.
If you want to use your file manager to alter files, you can start the file manager using gksu to give john temporary permission to do whatever it is you want to do without defeating the secure structure of having a nix based system.
First, to install gksu, run the following commands:
sudo apt-get update
sudo apt-get install gksu
Press ALT + F2 and then type:
and then press ENTER.
You will be prompted for your password and then the file manager will open with root permission so BE CAREFUL.