Drush

“drush” is a command line shell and scripting interface for Drupal, a veritable Swiss Army knife designed to make life easier for those of us who spend some of our working hours hacking away at the command prompt. In general
• drush is a command line shell and scripting interface for Drupal.
• drush is not a module
• It is valid to use the latest '7.x' (or master) no matter what your version of Drupal is. Drush is independent of Drupal version

Installation:
1. Untar the tarball into a folder outside of your web site (/path/to/drush)
2. Make the 'drush' command executable:
$ chmod u+x /path/to/drush/drush
3. (Optional, but recommended:) To ease the use of drush,
- create a link to drush in a directory that is in your PATH, e.g.:
$ ln -s /path/to/drush/drush /usr/local/bin/drush
NOTE ON PHP.INI FILES
Usually, php is configured to use separate php.ini files for the web server and the command line. To see which php.ini file drush is using, run:
$ drush status
Compare the php.ini that drush is using with the php.ini that the webserver is using. Make sure that drush's php.ini is given as much memory to work with asthe web server is; otherwise, Drupal might run out of memory when drush bootstraps it.
Drush requires a fairly unrestricted php environment to run in. In particular, you should insure that safe_mode, open_basedir, disable_functions and disable_classes are empty.
If drush is using the same php.ini file as the web server, you can create a php.ini file exclusively for drush by copying your web server's php.ini file to the folder $HOME/.drush or the folder /etc/drush. Then you may edit this file and change the settings described above without affecting the php enviornment of your web server.

4. Start using drush by running "drush" from your Drupal root directory.

Drush Commands:
You can find the drush commands from the url: http://drush.ws/