local(LIST)

             Declares the listed variables to  be  local  to  the
             enclosing  block, subroutine, eval or "do".  All the
             listed elements must be legal lvalues.  This  opera-
             tor  works  by  saving  the  current values of those
             variables in LIST on a hidden  stack  and  restoring
             them  upon  exiting  the  block, subroutine or eval.

             This means that called subroutines can  also  refer-
             ence  the  local  variable,  but not the global one.
             The LIST may be assigned to if desired, which allows
             you to initialize your local variables.  (If no ini-
             tializer is given for a particular variable,  it  is
             created  with an undefined value.)  Commonly this is
             used to name the parameters to a subroutine.   Exam-
             ples:

                  sub RANGEVAL {
                       local($min, $max, $thunk) = @_;
                       local($result) = '';
                       local($i);

                       # Presumably $thunk makes reference to $i

                       for ($i = $min; $i < $max; $i++) {
                            $result .= eval $thunk;
                       }

                       $result;
                  }

                  if ($sw eq '-v') {
                      # init local array with global array
                      local(@ARGV) = @ARGV;
                      unshift(@ARGV,'echo');
                      system @ARGV;
                  }
                  # @ARGV restored

                  # temporarily add to digits associative array
                  if ($base12) {
                       # (NOTE: not claiming this is efficient!)
                       local(%digits) = (%digits,'t',10,'e',11);
                       do parse_num();
                  }

             Note that local() is a run-time command, and so gets
             executed  every  time  through a loop, using up more
             stack storage each time until it's all  released  at
             once when the loop is exited.