perl -we 'use strict; %_ = %ENV; print $_{TERM},$/'
perl -we 'use strict; %@ = %ENV; print $@{USERNAME},$/'
perl -we 'use strict; %% = %ENV; print $%{HOME},$/'

##</code><code>##

perl -we 'use strict; %$ = %ENV; print ${$}{SHELL},$/'
# note the extra {} on this one to keep the parser from
# making the normally correct left turn of ${${SHELL}} and
# crying that $SHELL isn't declared...