What is Drush?
Drush is a command line shell and Unix scripting interface for Drupal. Drush core ships with lots of useful commands for interacting with code like modules/themes/profiles. Similarly, it runs update.php, executes sql queries and DB migrations, and misc utilities like run cron or clear cache.
Simply put, you can perform administrative tasks far more efficiently with Drush than you can with the Drupal administration control panel in the web browser. An efficient Drupal 7 developer must use Drush.
Download and install the Drush command-line software. There are a few ways you can do this.
If you are running Linux, you can most likely install Drush with the operating system’s native package manager. Operating system’s package manager may install an older version.
# sudo yum install drush
OS X with Homebrew
# brew install drush
# sudo apt-get install drush
Install Drush using Composer
If you have already installed Composer on your system, you can use it to install Drush.
composer global require drush/drush:6.*
Also want to make sure the Composer binaries directory is added to your system path.
sed -i ‘1i export PATH=”$HOME/.composer/vendor/bin:$PATH”‘ $HOME/.bashrc
Install Manually Drush
Manually download and install Drush, but you must have Composer already installed first. When you’re ready to manually install Drush:
# Create a bin directory for your user account and add to system path
echo “PATH=$HOME/bin:$PATH” >> ~/.bashrc
# Download and unzip the Drush software
wget -O $HOME/bin/drush.zip https://github.com/drush-ops/drush/archive/master.zip
unzip -d $HOME/bin $HOME/bin/drush.zip
# Install Drush dependencies with Composer (assumes `composer` is on system PATH)
# Create a symbolic link
ln -s $HOME/bin/drush-master/drush $HOME/bin/drush
Once you have downloaded and install the Drush software, you can open your Terminal/Console application, type
drush, and hit