Re: libunique -- stdout, stderr redirecting to running instance, and not calling client

[Paul Davis <paul linuxaudiosystems com>]

On Mon, Mar 14, 2011 at 5:21 PM, Michael Treibton
<mtreibton googlemail com> wrote:
> Hi all,
>
> I've an application using libunique -- which is working fine.  But one
> thing this application does is print out key information, for
> instance:
>
> % ./foo -z
> output_printed
>
> Which in this case, starts "foo" and prints out "output_printed".  On
> subsequent calls to foo, like this:
>
> % ./foo -z
> output_printed
>
> "output_printed" is sent to the STDOUT of the original "foo" process,

i think you need to change the semantics of -z. stdout is by
definition per-process, and so anything in your application that
prints to stdout will by definition print to stdout of that process.
you need to use a different mechanism to "printing". if you want the
second foo -z to display output generated by the initial instance, you
pretty much necessarily need to use IPC to get the data back to the
relevant process instance. printing to stdout is more or less broken
by definition.