How to fix my problem when trying to create a Drupal sub-theme with Drush? I get the following error when I try to run the "drush fst foundation-subtheme" command.  

sh-3.2# drush fst foundation-subtheme
The drush command 'fst foundation-subtheme' could not be found.  Run `drush cache-clear drush`  [error]
to clear the commandfile cache if you have installed new extensions.
Drush was not able to start (bootstrap) the Drupal database.                                    [error]
Hint: This may occur when Drush is trying to:
 * bootstrap a site that has not been installed or does not have a configured database. In this
case you can select another site with a working database setup by specifying the URI to use with
the --uri parameter on the command line. See `drush topic docs-aliases` for details.
 * connect the database through a socket. The socket file may be wrong or the php-cli may have
no access to it in a jailed shell. See http://drupal.org/node/1428638 for details.


Drush was attempting to connect to: 


  Drupal version         :  7.32
  Site URI               :  http://default
  
  Database driver        :  mysql
  Database hostname      :  localhost
  Database port          :  3306
  Database username      :  root
  Database name          :  drupal
  PHP executable         :  /usr/bin/php
  PHP configuration      :
  PHP OS                 :  Darwin
  Drush script           : 
  /Users/Marianna/.composer/vendor/drush/drush/drush.php   Drush version
  :  8.1.3                                                    Drush temp
  directory   :  /tmp
  Drush configuration    :
  Drush alias files      :
  Drupal root            :  /Users/Marianna/Documents/Sites/Link-New
  Drupal Settings File   :  sites/default/settings.php
  Site path              :  sites/default


I get the following error when I try to install foundation with drush:

sh-3.2# drush --uri=http://linkengineering en zurb_foundation
Command pm-enable needs a higher bootstrap level to run - you will need to invoke drush from a  [error]
more functional Drupal environment to run this command.
The drush command 'en zurb_foundation' could not be executed.                                   [error]
Drush was not able to start (bootstrap) the Drupal database.                                    [error]
Hint: This may occur when Drush is trying to:
 * bootstrap a site that has not been installed or does not have a configured database. In this
case you can select another site with a working database setup by specifying the URI to use with
the --uri parameter on the command line. See `drush topic docs-aliases` for details.
 * connect the database through a socket. The socket file may be wrong or the php-cli may have
no access to it in a jailed shell. See http://drupal.org/node/1428638 for details.


Drush was attempting to connect to: 


  Drupal version         :  7.32
  Site URI               :  http://linkengineering
  Database driver        :  mysql
  Database hostname      :  localhost
  Database port          :  3306
  Database username      :  root
  Database name          :  drupal
  PHP executable         :  /usr/bin/php
  PHP configuration      :
  PHP OS                 :  Darwin
  Drush script           : 
  /Users/Marianna/.composer/vendor/drush/drush/drush.php   Drush version
  :  8.1.3                                                    Drush temp
  directory   :  /tmp
  Drush configuration    :
  Drush alias files      :
  Drupal root            :  /Users/Marianna/Documents/Sites/Link-New
  Drupal Settings File   :  sites/default/settings.php
  Site path              :  sites/default
The issue mostly will be with environment/php and this is issue with MAMP (mismatch of path your MAMP-php and Server-php). Follow this link from that article.


  The Solution: A Symlink
  
  For the sake of ease, let’s just make your terminal sessions use the
  same PHP executable as MAMP. So run this:

$ mv /usr/bin/php /usr/bin/php.bak 
$ ln -s /Applications/MAMP/bin/php/php5.5.3/bin/php /usr/bin/php



But you need to check path as per your folders.