That comment on using the ping command reminded me of something.
A lot of people would write that chunk of code and create a socket on the system to do the ping (since it makes it OS independent)(Obviosuly doing it here was well outside the scope of an introductory tutorial).
I was working a co-op term and we wrote a perl script to ping all our hosts, so we could check if they came back up after power outages. It was written under Win 95 and used raw sockets. When we upgraded to NT, even though we did app support, we only had regular user rights on the local machines. That meant no permission to create raw sockets. We had to rewrite the script with an embedded DOS ping command in it and then 'grep' the output for the word 'Reply'.
Even though this was just a Python example, there are situations where things have to be written this way (OS specific)