$'      The string following whatever  was  matched  by  the
             last  pattern match (not counting any matches hidden
             within a BLOCK  or  eval  enclosed  by  the  current
             BLOCK).    (Mnemonic:   '  often  follows  a  quoted
             string.)  Example:

                  $_ = 'abcdefghi';
                  /def/;
                  print "$`:$&:$'\n";      # prints abc:def:ghi