Yes, but note that do{}while(); is not actually a loop. You can't use loop control mechanics like last and next. This is noted under Universal Blunders, page 529 in Camel 2:
Using loop control statements in do {} while. Although the braces in this control structure look suspiciously like part of a loop BLOCK, they aren't.
Yes, but this is a simple example and does not use any loop control statements. myocom stated in his reply that the while(sleep(1)) construct would sleep first before showing any output - the opposite of what the original author was trying to do in the sample code. In this case, the do {} while () is a perfectly acceptable WTDI.