perl -Mstrict -we"eval{require Tk;import Tk;1} or die $@;tkinit()->Button(-text=>1,-command=>sub{exit})->pack;MainLoop();"

# or

perl -Mstrict -we'eval{require Tk;import Tk;1} or die $@;tkinit()->Button(-text=>1,-command=>sub{exit})->pack;MainLoop();'