1*0699090bSGarrett WollmanThis is a simple program which demonstrates how to query the kernel 2*0699090bSGarrett Wollmanrouting mechanism using only a UDP socket. Pass it a hostname on 3*0699090bSGarrett Wollmanthe command line (sorry, it doesn't parse dotted decimal) and it will 4*0699090bSGarrett Wollmanprint out an IP address which names the interface over which UDP 5*0699090bSGarrett Wollmanpackets intended for that destination would be sent. 6*0699090bSGarrett WollmanA more sophisticated program might use the list obtained from SIOCGIFCONF 7*0699090bSGarrett Wollmanto match the address with an interface name, but applications programmers 8*0699090bSGarrett Wollmanmuch more often need to know the address of the interface rather than 9*0699090bSGarrett Wollmanthe name. 10