This may works.
$ /sbin/route get default route to: default destination: default mask: default gateway: 192.168.1.1 interface: en1 flags: <UP,GATEWAY,DONE,STATIC,PRCLONING> recvpipe sendpipe ssthresh rtt,msec rttvar hopcount mtu expire 0 0 0 0 0 0 1500 0
$ /sbin/route get default|grep interface:|awk '{print $2}' en1
Manpage of OSX's BSD style /sbin/route command: https://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man8/route.8.html
This may works.
$ /sbin/route get default DONE,STATIC, PRCLONING>
route to: default
destination: default
mask: default
gateway: 192.168.1.1
interface: en1
flags: <UP,GATEWAY,
recvpipe sendpipe ssthresh rtt,msec rttvar hopcount mtu expire
0 0 0 0 0 0 1500 0
$ /sbin/route get default|grep interface:|awk '{print $2}'
en1
Manpage of OSX's BSD style /sbin/route command: https:/ /developer. apple.com/ library/ mac/#documentat ion/Darwin/ Reference/ ManPages/ man8/route. 8.html