Install Drush for Drupal 7 on Ubuntu Linux 32/64bit
The Tutorial Shows You Step-by-Step How-to Install Drush Command Line Interface for Drupal 7 on Ubuntu 14.04 Trusty Tahr LTS i386/amd64 Linux Desktop/Server.
Drush is a command line shell and Unix scripting interface for Drupal. If you are unfamiliar with shell scripting, reviewing the documentation for your shell (e.g. man bash) or reading an online tutorial (e.g. search for “bash tutorial”) will help you get the most out of Drush.
Open a Command Line Terminal Window
(Press “Enter” to Execute Commands)
Or Login into the Shell…
How-to Install Composer Manager for PHP:Installing Composer for PHP
Installing Drush CLi for Drupal7 on Ubuntu
composer global require drush/drush:dev-master
Insert Drush into User Path
echo "export PATH=$PATH:$HOME/.composer/vendor/bin" >> $HOME/.bashrc
Testing Drush Installation
Getting Started with Drush 7 CLI Commands:Drush 7 Commands Quick-Start