or download this
$ perl -Mstrict -ew 'if(undef() eq undef()){print "true"}else{print "f
+alse"}'
Bareword "w" not allowed while "strict subs" in use at -e line 1.
...
Use of uninitialized value in string eq at -e line 1.
Use of uninitialized value in string eq at -e line 1.
true