for (0..3) {
  print "....\b\b\b\b";
  sleep 1;
}

##</code><code>##

print "....\b\b\b\b" and sleep 1 for (0..3);

##</code><code>##

for (0..3) {
  print "." and sleep 1 for (0..3);
  print "\b\b\b\b" and sleep 1;
}