perl -d <Your-program-file-name>

##</code><code>##

  DB<1> s
main::(junk.pl:10):     print $rec->{TEXT},"\n",
main::(junk.pl:11):        $rec->{SEQUENCE}[0],"\n",
main::(junk.pl:12):      $rec->{LOOKUP}{"dog"},"\n";
  DB<1> x  $rec -> [Buick]
Not an ARRAY reference at (eval 7)[/usr/lib/perl5/5.10.0/perl5db.pl:638] line 2.
  DB<2> x  $rec -> {LOOKUP} -> {cars}
0  'Buick'
  DB<3> x  $rec -> {LOOKUP} [0]
Not an ARRAY reference at (eval 9)[/usr/lib/perl5/5.10.0/perl5db.pl:638] line 2.
  DB<4> x  $rec -> {LOOKUP} {dog}
0  'hound'
  DB<5> q