Install latest version of php to ubuntu 12.04

Install php

sudo add-apt-repository ppa:ondrej/php5

sudo apt-get update
sudo apt-get install python-software-properties

sudo apt-get update

sudo apt-get install php5

php5 -v

ref: http://www.dev-metal.com/how-to-setup-latest-version-of-php-5-5-on-ubuntu-12-04-lts/

Install composer

curl -sS https://getcomposer.org/installer | php
sudo mv composer.phar /usr/local/bin/composer.phar

vim .bashrc

add 

alias composer='/usr/local/bin/composer.phar'

source  .bashrc