Re: [Sbcl-help] Problems with "broken pipe" error

[Leslie P. P. <sk...@vi...>]

On Wed, Apr 28, 2010 at 07:28:24PM +0300, Teemu Likonen wrote:
> * 2010-04-26 09:11 (+0200), Leslie P. Polzer wrote:
> 
> > Here's a quick working sketch:
> 
> > (without-package-locks
> >   (defun sb-impl::flush-standard-output-streams ()
> >     (ignore-errors
> >       (dolist (name '(*debug-io*
> >                       *error-output*
> >                       *query-io*
> >                       *standard-output*
> >                       *trace-output*
> >                       *terminal-io*))
> >         ;; FINISH-OUTPUT may block more easily than FORCE-OUTPUT
> >         (force-output (symbol-value name)))
> >       (values))))
> >
> >
> > (format t "one~%two~%three~%")
> 
> Redefining an internal function seems ugly. I do appreciate your help
> and efforts, though. So really, thank you.

It's just a kludge to fix this until we have a sane solution in upstream.
I happen to need this functionality too for one of my projects so I might
write a proper patch soon. Of course this will take some time, and more
still until the patch is committed.

 
> Unfortunately I don't understand the problem fully myself and most
> likely that's the reason I couldn't get your "quick working sketch"
> working. With the above code (at script's top level) and my original
> test script I still get the same "broken pipe" error when the output is
> piped to "head -n1".

There's a bunch of output preceding the actual program's output,
like the version/license banner.

When the pipe breaks before we have a chance to redefine
sb-impl::flush-standard-output-streams then our code won't change
anything.

Try the --script switch (cuts down banner size to one line)
and -n2 with head. Furthermore add another IGNORE-ERRORS around
the FORMAT form since the output might go straight to stdout
instead of being buffered.

I can post a full transcript next time if you can't get the same
results.

  Leslie