examples$ ./enum_if 
address: 127.0.0.1
   mask: 255.0.0.0
   flags: loopback 
  router: 127.0.0.1
address: 172.20.236.197
   mask: 255.255.0.0
   flags: local 
  router: 172.20.236.1
address: 192.168.253.1
   mask: 255.255.255.0
   flags: local 
  router: 192.168.253.1
address: 172.19.10.1
   mask: 255.255.255.0
   flags: local 
  router: 172.19.10.1
Local address: 172.20.236.197