This whole section deprecated as drush is installed with drupal - see instructions for installation of Drupal which has been edited to install via composer
The version of php installed on my server is 5.4
I would have liked to upgrade it, but the repo it was installed from (base) only has 5.4, and as I am only using Drupal 7 on this server, I left it as it was.
This does mean though that I am restricted to Drush7 too.
So I installed Drush with Composer.
First install Composer:
# cd /opt # wget https://getcomposer.org/installer # php installer # ln -s /opt/composer.phar /usr/local/bin/composer # rm installer
Next install Drush7 globally using Composer:
# mkdir /opt/drush # cd /opt/drush # composer init --require=drush/drush:7.* -n # composer config bin-dir /usr/local/bin # composer install
To update Drush in future, :
# cd /opt/drush # composer update