drop_index (KirbyBase::KBEngine)

    # File lib/kirbybase.rb, line 1471
        def drop_index(table, col_names)
            with_write_lock(table.name) do
                fptr = open(table.filename, 'r')
                new_fptr = open(table.filename+'temp', 'w')

                line = fptr.readline.chomp

                if line[0..0] == 'Z'
                    header_rec = unencrypt_str(line[1..-1]).split('|')
                else
                    header_rec = line.split('|')
                end

                col_names.each do |c|
                    temp_field_def = \
                     header_rec[table.field_names.index(c)+3].split(':')
                    temp_field_def = temp_field_def.delete_if {|x|
                        x =~ /Index->/
                    }
                    header_rec[table.field_names.index(c)+3] = \
                     temp_field_def.join(':')
                end

                if line[0..0] == 'Z'
                    new_fptr.write('Z' + encrypt_str(header_rec.join('|')) +
                     "\n")
                else
                    new_fptr.write(header_rec.join('|') + "\n")
                end

                begin
                    while true
                        new_fptr.write(fptr.readline)
                    end
                # Here's how we break out of the loop...

                rescue EOFError
                end

                # Close the table and release the write lock.

                fptr.close
                new_fptr.close
                File.delete(table.filename)
                FileUtils.mv(table.filename+'temp', table.filename)
            end
        end