Usage DO {...} [WHILE (EXP)]

Causes the commands enclosed within the {} block to be executed at least
once.  An optional "while (exp)" predicate is allowed to determine when
the looping should end.  If no trailing WHILE is present, then the commands
will be executed only once (just as if you had put "while (0)" there)

DO without a WHILE predicate is the same as the EVAL command.

See also: WHILE
	  EVAL
