In this case, Raspi SMS server is made using PHP script. There are many third-party open source PHP SMS servers like gammu-php, kalkun, etc, but here we have built a simple PHP SMS server.
PHP script. The small script (sms.php) is written in PHP. It will open in the browser window if Apache and PHP are installed on your Raspi.
Set up Apache Web server on Raspi using the following command:
Copy and paste sms.php program into Apache document root directory of Raspi, which is normally /var/www/html or whatever you have set.