Script to force an ip onto wlan0 on RPi

#!/bin/sh

_MY_IP=`ifconfig | awk '/192.168.111/{print substr($2,6)}'`

_NO_ATTEMPTS=0

while test -z $_MY_IP && test $_NO_ATTEMPTS -lt 10
do
   _NO_ATTEMPTS=`expr $_NO_ATTEMPTS + 1`
   printf "No IP on wlan0, retrying (%i) ...\n" "$_NO_ATTEMPTS"
   sudo service hostapd stop
   sudo service isc-dhcp-server stop
   sudo ifdown wlan0
   sudo ifup wlan0
   sudo ifconfig wlan0 192.168.111.1
   sudo service hostapd start
   sudo service isc-dhcp-server start
   _MY_IP=`ifconfig | awk '/192.168.111/{print substr($2,6)}'`
done

if test -z $_MY_IP
then
   echo "No IP obtained on wlan0 after 10 attempts, giving up."
fi