Re: [Help-bash] get pid of exited process

[Stas Sergeev]

03.01.2016 20:10, Stas Sergeev пишет:
> > If even with that in mind you want to proceed, you can do this:
> Thanks! That's a nice trick that works well for me.
>
> The reason I need this, is for the program-specific cleanup.
> Programs usually create the pipes and sockets, embedding
> the PID in their names. If such program crashes, the startup
> script needs to do the cleanup. For that it needs to know the
> pid of the program it was executing.
> I think such scenario is valid and rather common, so I am a
> bit upset bash does not have a native support for this.
> But your trick is almost as convenient as the native support.
Ah, except for the nasty side-effect!
What I do, is:

P=$(echo $BASHPID; exec my_app)

But the problem is that the stdout of my_app also goes into P.
Example:
$ P=$(echo $BASHPID; exec /bin/echo test)
$ echo $P
7535 test

This is not what I need. I need my_app to still use its tty.
The work-around I can think of, is:

exec 3>&1
P=$(echo $BASHPID; exec 1<&3; exec $COMMAND)
exec 3>&-

but is there a simpler fix?
I guess there is some syntax to use another FD to pass
the subshell's output to the parent - what would it be? :)