keys(ASSOC_ARRAY)

     keys ASSOC_ARRAY

             Returns a normal array consisting of all the keys of
             the  named associative array.  The keys are returned
             in an apparently random order, but it  is  the  same
             order as either the values() or each() function pro-
             duces (given that the associative array has not been
             modified).   Here  is  yet another way to print your
             environment:

                  @keys = keys %ENV;
                  @values = values %ENV;
                  while ($#keys >= 0) {
                       print pop(@keys), '=', pop(@values), "\n";
                  }

             or how about sorted by key:

                  foreach $key (sort(keys %ENV)) {
                       print $key, '=', $ENV{$key}, "\n";
                  }