#Installation In terminal, copy/paste the following to create a ubin (user bin) folder if it doesn't exist already and add to paths.

sudo mkdir /usr/ubin
sudo chown $USER /usr/ubin
echo "export PATH=\"/usr/ubin:\$PATH\"" >> ~/.profile

Then move the calc.php and calc file over to /usr/ubin/ and make sure calc is executable by chmod +x /usr/ubin/calc