[vorbis-dev] piping vorbize's stdout/stderr

[Peter Surda]

On Mon, Jul 31, 2000 at 11:14:11AM -0700, Monty wrote:
> > Hi!
> > I want to pipe stdout/stderr from vorbize for wrapper scripts. But as it
> > doesn't send any "\n"s it doesn't work correctly. I solved it by adding 
> > 
> > if (param.verbose == 1) {
> >   fprintf (stderr, "\n");
> > }
> That actually isn't guaranteed to work.  The proper thing to do is 
> fflush(stderr).
Well, I guess we're both right to some extent. But unless I use a "\n", 
---------cut----------
open PIPE, "vorbize blahblahblah|";
while (<PIPE>) {
        if (/(\d+\.\d\%)/) {
                $status{perc} = $1;
        }
}
close PIPE;
---------cut----------

(in Perl) doesn't work. Well it does but the whole progress is treated as 1
line after the encoding has finished. I guess I don't have to explain why this
is unwanted :-)

Although fdflush indeed results in better synchronization, I still have to use
the "\n".

OTOH I could do a 
--------cut--------
system ("mkfifo", "/tmp/pipe.stuff");
start_a_new_thread_for system ("vorbize", "blahblahblah", ">&/tmp/pipe.stuff");
sysopen (SOMETHING, "/tmp/pipe.stuff", O_RDONLY|O_SOMETHING_ELSE);
while (tread_running) {
        sysread(SOMETHING); # problematic because a line of output doesn't 
                            # have a fixed length
        find_out_percent;
}
close (SOMETHING);
--------cut--------
but that's a hell more complicated and prone to bugs.

> Monty

Bye,

Peter Surda (Shurdeek) <surda at bigfoot.com>, ICQ 10236103, +4369910964300


--
   If Bill Gates had a dime for every time a Windows box crashed...
                ...Oh, wait a minute, he already does.

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