file transfer requirement

normal user could need to post file inside his phone to a PC, to another user’s phone , or to another device. without need to connect to that user. he might be just need it for one time only.

on his phone, he just need to install this app. and select which file to transfer. on another phone, it will display a mic code. it could be a number , or could be any thing easy to set target. to transfer file to that target.

target phone or browser will be post the file and accept , show progress , allow to save to local drive.

It should be fast, no limit the file size.

Ulimit mac file handle


* soft nofile 65535
* hard nofile 65535
session required

# su – oracle
$ ulimit -Hn
$ ulimit -Sn

# vi /etc/sysctl.conf

Append a config directive as follows:
fs.file-max = 500000

# sysctl -p

Enable developer mode: Nexus 6p

Open the Settings app.
Scroll down to the bottom and select About phone.
Scroll to the bottom and press Build number 7 times (you’ll see a confirmation that you are now a developer), press the back button.
Developer options will now appear at the bottom of Settings, select it.

PPTP VPN VPS Ubuntu 16

apt-get install pptpd

Modify /etc/pptpd.conf find ‘localip’ and ‘remoteip’ and replace with


After add the ip scope, we can continue adding users VPN with modifying /etc/ppp/chap-secrets, for example

max pptpd 123456 *

modify /etc/ppp/options,




Run following, Pay attention to eth0, it may need change to right interface name

$ sudo sysctl -p

$ sudo /etc/init.d/pptpd restart

$ sudo /sbin/iptables -t nat -A POSTROUTING -s -o eth0 -j MASQUERADE

cat > /etc/init.d/pptpenable
/sbin/iptables -t nat -A POSTROUTING -s -o eth0 -j MASQUERADE


$ chmod +x vpnrule
$ update-rc.d vpnrule defaults



/etc/ufw/before.rules add below rules. and then restart ufw

# NAT table rules

# Forward traffic through eth0 - Change to match you out-interface

# don't delete the 'COMMIT' line or these nat table rules won't
# be processed

#adding this rule to the file /etc/ufw/before.rules before the line # drop INVALID packets ...

-A ufw-before-input -p 47 -j ACCEPT

#Then Run
 sudo ufw disable && sudo ufw enable