Perl 5 version 12.1 documentation
redocommand restarts the loop block without evaluating the conditional again. The
continueblock, if any, is not executed. If the LABEL is omitted, the command refers to the innermost enclosing loop. Programs that want to lie to themselves about what was just input normally use this command:
Note that a block by itself is semantically identical to a loop that executes once. Thus
redoinside such a block will effectively turn it into a looping construct.