Internet connection goes down periodically on macos and needs to be restarted by turning wifi on and off again. Sigh.

fix_web.sh

#!/bin/bash
# Adapted from https://stackoverflow.com/questions/6118948/bash-loop-ping-successful.
# Network connection mysteriously dies; ping every N seconds, and if ping fails
# turn wifi off and on again, which seems to fix it. 

echo "run this script with sudo!"
echo "Starting ..."

DOWN=0
while true; do
    ping -c 3 google.com > /tmp/ping.$
    if [ $? -eq  0 ]; then
        echo -n $(date +"%a, %b %d, %r") "-- "
        cat /tmp/ping.$ | tail -1

        echo -n $(date +"%a, %b %d, %r") "-- " >> netstats.txt
        cat /tmp/ping.$ | tail -1 >> netstats.txt

        if [ $DOWN -eq 1 ]; then
            DOWN=0
            say connection restored
        fi
    else
        NET=`networksetup -getairportnetwork en0 | cut -d':' -f2 | xargs`
        say connection to $NET is down
        DOWN=1
        echo $(date +"%a, %b %d, %r") "-- failed ping; toggling interface"
        echo -e $(date +"%a, %b %d, %r") "PING FAILED" >> ./network_interruptions.txt

        echo "Disconnecting from $NET..."
        # https://www.cyberciti.biz/faq/linux-unix-sleep-bash-scripting/
        networksetup -setnetworkserviceenabled Wi-Fi off
        sleep 5  # Give the wifi time to disconnect.

        networksetup -setnetworkserviceenabled Wi-Fi on
        # testing if this leads to faster connect
        networksetup -setairportnetwork en0 $NET 
        # sleep 10 # Give wifi enough time to connect before rechecking 
        # (need this if sleep at bottom of loop gets too short)
    fi

    # Checking ping every N seconds seems fine.
    sleep 10
done