# File lib/chef/knife/role_bulk_delete.rb, line 32
      def run
        if @name_args.length < 1
          ui.error("You must supply a regular expression to match the results against")
          exit 1
        end

        all_roles = Chef::Role.list(true)

        matcher = /#{@name_args[0]}/
        roles_to_delete = {}
        all_roles.each do |name, role|
          next unless name =~ matcher
          roles_to_delete[role.name] = role
        end

        if roles_to_delete.empty?
          ui.info "No roles match the expression /#{@name_args[0]}/"
          exit 0
        end

        ui.msg("The following roles will be deleted:")
        ui.msg("")
        ui.msg(ui.list(roles_to_delete.keys.sort, :columns_down))
        ui.msg("")
        ui.confirm("Are you sure you want to delete these roles")

        roles_to_delete.sort.each do |name, role|
          role.destroy
          ui.msg("Deleted role #{name}")
        end
      end