But, if you are "stuck" on Unix (which is really a good thing), you can refer to this node (or many others if you search for fork, exec and wait). Basically, you will fork off each independent process, collecting their process ids and then have the parent script wait until it receives a SIGCHLD from each one signaling it has finished.
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echo S 1 [ Y V U | perl -ane 'print reverse map { $_ = chr(ord($_)-1) } @F;'