Re: while sleep 1;do :& done vs. C-z

[Chet Ramey]

Dan Jacobson wrote:

> Do
> $ while sleep 1;do :& done
> Then after a while type C-z bg RET
> Notice how our loop poops out quickly. Contrast that with
> $ while sleep 1; do :& done&
> which we can fg C-z bg all we like.

Consider what you're doing, and where in the process tree
you're doing it.  Job control works only on individual processes.

I suspect that chances are pretty good you're stopping the
`sleep 1' process in the first example, which causes it to return
to the calling shell with a non-zero exit status (probably
128+SIGTSTP).  That breaks the loop.

In your second example, you're manipulating the subshell started
to run the loop in the background.  Since that's a single process, it's
possible to stop and start it.

Chet