You can get the original (running in dosbox) from gog.com for a couple of bucks. Maybe it's just nostalgia, but I preferred the original too.
ch := make(chan int, 1)
var send chan<- int = ch
var recv <-chan int = ch
send <- 1 // ok
<- recv // ok
recv <- 1 // invalid operation: recv <- 1 (send to receive-only type <-chan int)
<- send // invalid operation: <-send (receive from send-only type chan<- int) execlp("mv", "mv", src, dest, NULL);