initAP

#https://nims11.wordpress.com/2013/05/22/using-hostapd-with-dnsmasq-to-create-virtual-wifi-access-point-in-linux/
#!/bin/bash
#Initial wifi interface configuration
ifconfig $1 up 10.0.0.1 netmask 255.255.255.0
sleep 2
 
###########Start dnsmasq, modify if required##########
if [ -z "$(ps -e | grep dnsmasq)" ]                             
then
 dnsmasq
fi
###########
 
#Enable NAT
iptables --flush
iptables --table nat --flush
iptables --delete-chain
iptables --table nat --delete-chain
iptables --table nat --append POSTROUTING --out-interface $2 -j MASQUERADE
iptables --append FORWARD --in-interface $1 -j ACCEPT
 
#Thanks to lorenzo
#Uncomment the line below if facing problems while sharing PPPoE, see lorenzo's comment for more details
#iptables -I FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
 
sysctl -w net.ipv4.ip_formard=1

#start hostapd
sudo hostapd -B /home/pi/.hostapd.min.conf
killall dnsmasq

Why do you start dnsmasq, start hostapd then kill dnsmasq? Does hostapd run in blocking (non-daemon) mode?

In the original script it blocks. I have to hit ctrl+c to stop hostapd. I added the -B as suggested there but I haven't been using the script much but there's a note in the link about "taking care of dnsmasq". I honestly don't know about how all of these work but the script works nicely. Another nice thing about it is you can also select interfaces when activating it like ./initAP eth0 wlan1 (source interface to access point interface).