print "'$_' is empty string" if $_ =~ /^$/;

##</code><code>##

print "Empty   matches ^\$  --> ", ("" =~ /^$/ ? 'yes' : 'no'), "\n";
print "Newline matches ^\$  --> ", ("\n" =~ /^$/ ? 'yes' : 'no'), "\n";
print "Empty   matches ^\\z --> ", ("" =~ /^\z/ ? 'yes' : 'no'), "\n";
print "Newline matches ^\\z --> ", ("\n" =~ /^\z/ ? 'yes' : 'no'), "\n";