Script to determine which web server at ip addresses

Applications Web Development
1

how do we determine if ip addresses are hosting IIS version 7.x or Apache 2.2.x. ?

2 
nmap -p 80 -sV $IP
3

Thanks . sorry did not really understand do you mind explaining? and how do we print which ip is iis and which one is apache?

4

The output of nmap is fairly self explanatory, substitute the actual IPs for $IP in the above, or look up the nmap manual at insecure.org.