wpa_supp_conf.txt

 # cat /etc/wpa_supplicant/wpa_supplicant.conf
update_config=1
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel
ctrl_interface=/var/run/wpa_supplicant
eapol_version=1
ap_scan=1
fast_reauth=1
# Only WPA-PSK is used. Any valid cipher combination is accepted.
network={
        ssid="987654321"
        proto=WPA
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP WEP104 WEP40
        psk=xxxxxxsecretxxxxxx
        priority=2
}

This is minus all the comment cruft