My macbook has been encountering sporadic wifi issues in its old age. To cope with this I made a script designed to reset my wifi should this connection drop occur.

bandaid.sh

#!/bin/bash

# Steps to run, either add execution and run, or run the following
# bash <path-to-script>/bandaid.sh &

# To kill script find the pid with ps and kill or run the following
# kill -9 $(pgrep -f bandaid.sh)

# My System: macOS High Sierra, Version 10.13.6
# Bash version: GNU bash, version 3.2.57

# My setup
# 2 Aliases in my bash profile for running and killing
# alias bon='bash <path-to-script>/bandaid.sh &'
# alias boff='kill -9 $(pgrep -f bandaid.sh)'

# Get exit code for if screen is active
# Based on https://stackoverflow.com/a/39546692
check_for_active_screen() {
    ioreg -c AppleBacklightDisplay | grep brightness | grep "dsyp\"={\"min\"=0,\"max\"=2,\"value\"=2}" > /dev/null
}

# Get exit code of two attempts at pinging google's public dns server
check_for_connection() {
  ping -c2 -W2 '8.8.8.8' > /dev/null 2>&1
}

# Reset my wifi connection
# Based off of https://osxdaily.com/2011/05/31/enable-disable-airport-wireless-connections-command-line/
reset_wifi() {
  networksetup -setairportpower "Wi-Fi" off > /dev/null 2>&1
  sleep 1
  networksetup -setairportpower "Wi-Fi" on > /dev/null 2>&1
}

# If I want to record instances of restarts
# output_file='<path-to-output>/output.out'

while :; do
  check_for_active_screen
  # Verify that we are not in sleep mode
  if [ $? == 0 ]; then
    check_for_connection
    # Verify that our connection is down
    if [ $? != 0 ]; then
      # Reset wifi
      reset_wifi
      # If I want to record instances of restarts
      # date >> $output_file
      # echo 'Wifi Restarted' >> $output_file
      # echo '---------------' >> $output_file
    fi
  fi
  sleep 7
done