How to get online players list?

[aimgame]

There is a script in a server side archive - Tools\PHP\GetOnlinePlayers.php 

Can anyone tell how it works? I've tried to test it, and here's what i get:
Parse error: syntax error, unexpected '.0' (T_DNUMBER) in C:\xampp\htdocs\main\GetOnlinePlayers.php on line 14

If i change 127.0.0.1 to localhost it says:
Fatal error: Class 'Redis' not found in C:\xampp\htdocs\main\GetOnlinePlayers.php on line 13