Another, more in-depth version of the above, that gives you more control over script output:

my $proc = Proc::Async.new: 
  "bash", "-c", 
  "echo \"Hallo, sleeping for 120 seconds ...\"; sleep 120"; 

react {
  whenever $proc.stdout.lines {
        # Act on output from command. In this case, we just print it.
        say ‘line: ’, $_
  }
  whenever Supply.interval(10) {
        # Handler. Occurs every 10 seconds.
        say "In handler..."
  }
  whenever $proc.start {
        say ‘Proc finished: exitcode=’, .exitcode, 
            ‘ signal=’, .signal;
        # Gracefully jump from the react block. 
        # Also stops the handler!
        done; 
  }
  whenever Promise.in(300) {
        # Optional time-out code that fires in 300 seconds [5 minutes]
        # Handle as you see fit, but it's probably best to end with:
        done;
  }
}
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