telnet can be used to connect you to servername on a specified port. You can gather information from the data returned from that connection:
telnet servername.com port
Then type:
HEAD / HTTP/1.0
bash-3.2# telnet 310.210.7.222 80
Trying 310.210.7.222…
Connected to servername.com.
Escape character is ‘^]’.
HEAD / HTTP/1.0
HTTP/1.1 200 OK
Date: Fri, 20 May 2016 15:00:24 GMT
Server: Apache/2.2.3 (Red Hat)
X-Powered-By: PHP/5.3.3
Connection: close
Content-Type: text/html; charset=UTF-8
You can see from this example, that the Apache version and the PHP version are available via this method.
