ping puzzle

[jc at trillian.mit.edu (John Chambers)]

William Holt writes:

| what happens when you redirect stdout to stderr, and then redirect stderr? ie:
| ping x.x.x.x 2>A 1>&2
| cat A

What happens is that the ping  hangs,  of  course,  so  I  don't  get
another  shell prompt, making the cat moot.  So I ran the ping in the
background. For x.x.x.x my unreachable host, A remained at zero bytes
for a long time.  I suppose it will eventually get some data, after a
few hours, but by then the data won't be interesting any more.