Script to be called from cron to check Raspberry Pi's wireless connection

wireless_check.sh

#!/bin/bash

# The address of the wireless access point itself
GATEWAY=`netstat -nr | grep wlan0 | grep G | awk '{ print $2 }'`

# Let's try and contact the wireless access point
ping -c 1 $GATEWAY

# Did we succeed? (ping will make $? equal to 1 if it failed, or 0 if it succeeded)
if [[ $? == 1 ]]; then
  # Uh oh, couldn't contact the access point.
  # Let's bring the wireless down
  wpa_cli disconnect
  ifconfig wlan0 down
  sleep 5

  # and then bring it back up
  ifconfig wlan0 up
  wpa_cli reassociate
fi

# exit 0 to indicate we are happy
exit 0