use strict;
use WWW::Google::Calculator;
use Data::Dumper;

&calculate('100 cm in inches');

sub calculate {
        my $what = $_;
        my $calc = WWW::Google::Calculator->new;
        my $result = $calc->calc($what);
        print Dumper($result);
        if(!$result) {
                print "No result\n";
        } else {
                print "Result\n";
        }
}

# Produces
# $VAR1 = undef;
# No result