Pinging from a C/C++ program
EDIT I saw after I posted, you are on Ubuntu. However someone searching this question may still find these links helpful for Windows.
Ping: Raw Sockets Method: http://tangentsoft.net/wskfaq/examples/rawping.html
Implementing Internet Pings Using Icmp.dll: http://support.microsoft.com/default.aspx?scid=kb;en-us;170591
IcmpSendEcho Function: http://msdn.microsoft.com/en-us/library/aa366050%28VS.85%29.aspx
Ping for Windows: http://www.codeproject.com/KB/IP/winping.aspx
This post is old but I think the following link will help future people lookign for a good explanation on how to create a Ping request.