How to setup system Login banner and Login message

edit the "/etc/issue" and "/etc/motd" files

network security using iptables

http://www.cyberciti.biz/faq/linux-detect-port-scan-attacks/

iptables setting

 # Basic setup
 iptables --flush
 iptables -P FORWARD DROP
 iptables -P OUTPUT ACCEPT
 iptables -P INPUT DROP
# Allow SSH
 iptables -A INPUT  -i eth0 -p tcp --dport 22  -j ACCEPT
 iptables -A OUTPUT -o eth0 -p tcp --sport 22  -j ACCEPT
# Allow local loopback
 iptables -A INPUT -i lo -j ACCEPT
 iptables -A OUTPUT -o lo -j ACCEPT
# Allow DNS
 iptables -A OUTPUT -p udp -o eth0 --dport 53 -j ACCEPT
 iptables -A INPUT  -p udp -i eth0 --sport 53 -j ACCEPT
# Allow ping
 iptables -A OUTPUT -p icmp --icmp-type echo-request -j ACCEPT
 iptables -A INPUT  -p icmp --icmp-type echo-reply -j ACCEPT
# Allow http
 iptables -A INPUT  -i eth0 -p tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT
 iptables -A OUTPUT -o eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
# Allow https
 iptables -A INPUT  -i eth0 -p tcp --sport 443 -m state --state ESTABLISHED -j ACCEPT
 iptables -A OUTPUT -o eth0 -p tcp --dport 443 -m state --state NEW,ESTABLISHED -j ACCEPT
# Printer (ipp=631, cups=515)
 iptables -A OUTPUT -p tcp -d 192.168.60.157  --dport 515 -j ACCEPT
 iptables -A INPUT  -p tcp -s 192.168.60.157  --sport 515 -j ACCEPT

How to print a regular file to pdf from command line

http://askubuntu.com/questions/27097/how-to-print-a-regular-file-to-pdf-from-command-line

enscript my_text_file.txt -o - | ps2pdf - output.pdf

enscript -B -PPDF test.txt

unoconv -f pdf test.txt

how to install qt5 + phone app devel tool

http://developer.ubuntu.com/get-started/gomobile/

How to build Goto blas using Intel compilers

Download GotoBlas http://www.tacc.utexas.edu/tacc-projects/gotoblas2

make  FC=ifort   CC=icc  BINARY=64   USE_THREAD=0

The last option is to build without thread.  Output message:

 GotoBLAS build complete.

  OS               ... Linux             

  Architecture     ... x86_64               

  BINARY           ... 64bit                 

  C compiler       ... INTEL  (command line : icc)

  Fortran compiler ... INTEL  (command line : ifort)

  Library Name     ... libgoto2_prescott-r1.13.a (Single threaded)  

how to disable touch pad

Login as root.

$ xinput list
 You will see results similar to

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=15   [slave  pointer  (2)]
⎜   ↳ Logitech USB Receiver                     id=11   [slave  pointer  (2)]
⎜   ↳ Logitech USB Receiver                     id=12   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Video Bus                                 id=8    [slave  keyboard (3)]
    ↳ Sleep Button                              id=9    [slave  keyboard (3)]
    ↳ USB 2.0 UVC VGA WebCam                    id=10   [slave  keyboard (3)]
    ↳ Asus WMI hotkeys                          id=13   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=14   [slave  keyboard (3)]

The touchpad id is 15. To disable it:

$ xinput set-prop 15 "Device Enabled" 0

to re-enable it

$ xinput set-prop 15 "Device Enabled" 1