perl -e "printf(qq(%b),1024*1024*1024*1024)" #overflow!
 perl -e "print unpack(qq(B*), pack(qq(L), 1024*1024*1024*1024)) # ditto
 perl -e "print unpack(qq(B*), pack(qq(L2), 1024*1024*1024*1024)) # ditto