Wifi - Raspbian - RetroPie - Command Line
# https://learn.adafruit.com/adafruits-raspberry-pi-lesson-3-network-setup/setting-up-wifi-with-occidentalis
# edit interfaces using:
# sudo nano /etc/network/interfaces
# ignore lines above
# -----------------
auto lo
iface lo inet loopback
iface eth0 inet dhcp
allow-hotplug wlan0
auto wlan0
iface wlan0 inet dhcp
wpa-ssid "ssid"
wpa-psk "password"