I have a rspbryPI connected to Ethernet and with a Mac (though USB cable).
I m trying to SSH in the pi but I don't know the ip address.
I have tried :

 ifconfig

but I have I can't see eth0


 lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
	 options=3<RXCSUM,TXCSUM>
	 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
	 inet 127.0.0.1 netmask 0xff000000 
	 inet6 ::1 prefixlen 128 
 gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
 stf0: flags=0<> mtu 1280
 en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	 options=2b<RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4>
 ether a8:20:66:09:f8:36 
	 media: autoselect (none)
	 status: inactive
 en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
 	 ether 7c:d1:c3:d8:b5:dd 
	 inet6 fe80::7ed1:c3ff:fed8:b5dd%en1 prefixlen 64 scopeid 0x5 
	 inet 192.168.91.16 netmask 0xffffff00 broadcast 192.168.91.255
 	 media: autoselect
 	 status: active
 fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 4078
 lladdr 00:3e:e1:ff:fe:7f:a0:82 
	 media: autoselect <full-duplex>
	 status: inactive
 p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304
	 ether 0e:d1:c3:d8:b5:dd 
	 media: autoselect
 status: inactive