Exercise 3: Getting the Prompt Back From a Noisy Command — Possible Solution
==============================================================================

  $ ping localhost
  64 bytes from localhost ... (lines keep coming)
  ^Z                                (press Ctrl-Z)
  [1]+  Stopped                 ping localhost
  $ bg
  [1]+ ping localhost &

The prompt is back and ping keeps running.

The problem that remains: ping's output still goes to your terminal,
so its lines keep appearing in the middle of whatever you type. Once
a process is running, the shell can't redirect its output somewhere
else. (Stop it when finished with: kill %1)

How to start it differently:

  $ ping localhost > ping.log 2>&1 &

The output goes to a file, which you can check any time with
`tail ping.log` or `tail -f ping.log`. Alternatively, start it in its
own screen window (Chapter 4), where its output has a terminal of its
own and never mixes with your other work.

WHY THIS WORKS AS AN ANSWER
------------------------------
It shows that Ctrl-Z plus bg frees the prompt but not the screen, and
that output redirection has to be decided when the command starts.