Perl5 リファレンス

       quotemeta EXPR

               Returns the value of EXPR with all non-
               alphanumeric characters backslashed.  (That is,
               all characters not matching `/[A-Za-z_0-9]/' will
               be preceded by a backslash in the returned string,
               regardless of any locale settings.)  This is the
               internal function implementing the `\Q' escape in
               double-quoted strings.

               If EXPR is omitted, uses `$_'.