ubuntu create Wifi hot point（AP） by hostapd and dhcp3-server

Ubuntu 12.04 LTS
Propre install depend package:
1.apt-get install  hostapd dhcp3-server
2.run shell  on you notbook.

#!/bin/bash
# ai hostapd dhcp3-server
iw list|grep '* AP'
[ $? -ne 0 ] && echo "No device support AP mode." && exit

sudo ifconfig wlan0 192.168.0.1 netmask 255.255.255.0
sudo sysctl -w net.ipv4.ip_forward=1
sudo iptables -t nat -F
sudo iptables -t nat -A POSTROUTING -j MASQUERADE
sudo pkill -9 dhcpd

if [ ! -f /etc/apparmor.d/disable/usr.sbin.dhcpd ]; then
sudo ln -s /etc/apparmor.d/usr.sbin.dhcpd /etc/apparmor.d/disable/
sudo /etc/init.d/apparmor restart
fi

cat > /tmp/dhcpd.conf << EOF
default-lease-time 600;
max-lease-time 7200;
subnet 192.168.0.0 netmask 255.255.255.0
{
range 192.168.0.2 192.168.0.250;
option domain-name-servers 8.8.8.8;
option routers 192.168.0.1;
}
EOF
sudo dhcpd wlan0 -cf /tmp/dhcpd.conf -pf /var/run/dhcp-server/dhcpd.pid

cat > /tmp/hostapd.conf << EOF
interface=wlan0
driver=nl80211
ssid=`hostname`-hostapd
hw_mode=g
channel=11
auth_algs=1
# 如果需要开启密码，wpa=1。
wpa=0
wpa_passphrase=12345678
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
EOF
sudo hostapd -d /tmp/hostapd.conf