Re: Proposed option for "timeout" -- don't wait for sub-command to exit

[Pádraig Brady]

On 14/04/2023 19:49, Dale R. Worley wrote:
> Infrequently but repeatedly I've wanted a shell script to be able to
> start a background command, wait up to a certain duration for the
> command to finish, and then if it hasn't finished, the script continues,
> leaving the background command to continue executing.  Other people
> desire this, too, e.g.
> https://unix.stackexchange.com/questions/84973/timeout-without-killing-process-in-bash
> You can get this effect (without a wait loop) using "sleep NNN & wait -n
> ...", but you get extraneous job control output and it's awkward to
> code.
>
> Gnu "timeout" is the utility I would expect to implement this
> functionality, but it does not -- timeout won't exit until the
> sub-command exits no matter how you invoke it.
>
> So I am proposing adding an option to "timeout" viz. "-n/--no-wait"
> whose effect is "after the timeout is triggered and timeout sends the
> specified signal(s), timeout continues without waiting for the command
> to exit".  When this combined with "--signal=0", "timeout" will behave
> as I desire.
>
> Opinions?
>
> Dale

A bit of an unusual use case.
What about the albeit slightly hacky solution presented in that SO thread?

  timeout --foreground 3 sh -c 'possibly_slow_program;exit'

cheers,
Pádraig