Generalised Suffix Tree - Ruby

gem install suffix_tree_ruby
           or
gem 'suffix_tree_ruby', '~> 0.0.1'

Open a ruby interactive console:

require 'suffix_tree'

To create Suffix tree

tree = SuffixTree::Base.new(["sandollar", "sandlot", "handler", "grand", "pantry"])
tree.build

To get the longest common substring from all the words

tree.longest_common_substring
=> "an"

To get the longest common substring from at least k strings

tree.longest_common_substring(2)
=> "sand" # from the first 2 strings

tree.longest_common_substring(3)
=> "and" # from first 3 strings

Referrances

Suffix Tree Ruby is released under the MIT License.