Modify smb.conf to allow guest access to "public" share, using with asuswrt-merlin

public_share.sh

#!/bin/sh

# Grant guess access
sed -i '/\[public\]/,/^\[/ s/invalid users.*/guest only = yes\nwritable = yes/' /etc/smb.conf

# Remove user-specific ACLs
sed -i '/\[public\]/,/\[/ {/^\(valid\|invalid\|read\|write\)/d}' /etc/smb.conf

# Kill samba processes running
for pid in $(ps -w | grep [s]mbd | awk '{ print $1 }')
do
        kill $pid 2> /dev/null
done

# Restart samba with modified config
smbd -D -s /etc/smb.conf

Posted about it here: http://iambelmin.com/2015/12/30/public-samba-share-on-an-asuswrt-merlin-router/