Remember wifi names and ip addresses - in case the router's dhcp stops working you can still reconnect to it

crontab

# chmod +x wifiremember.sh, then
# type `crontab -e` and add this line :
* * * * * $HOME/wifiremember/wifiremember.sh

wifiremember.sh

# create the wifiremember directory in the user's home directory if it doesn't exist yet
mkdir -p $HOME/wifiremember
# the .txt file we want to save to
FILE=$HOME/wifiremember/wifinetworks.txt

# read current wifi name
WIFINAME="$(/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I | awk '/ SSID/ {print substr($0, index($0, $2))}')"
# read current ip from en0
IPINFO="$(/sbin/ifconfig en0|/usr/bin/grep inet| /usr/bin/sed -e 's/^[[:space:]]*//')"
# add the result to one line
LINE="Wifi: "$WIFINAME" IP: "$IPINFO
#only add line to wifinetworks.txt if it doesn't exist already
/usr/bin/grep -qF "$LINE" "$FILE" || echo "$LINE" >> "$FILE"