[rrd-developers] Re: BUG: attempt to put segment in horiz list twice ??

Ruud H.G. van Tol rvtol at isolution.nl
Wed Jul 27 18:32:08 MEST 2005


Per Jessen:

> [system()]
> when I use "rrdtool graph -"

I read news://news.gmane.org/gmane.comp.db.rrdtol.user later
and saw how you use rrdtool.


> The code that produces good PNGs but make the browser hang:
>
>         oldstdout=dup(1);       // take a copy of stdout
>         oldstderr=dup(2);
>         dup2(s,1);              // make stdout = s
>         close(2);               // close stderr
>
>         system(buffer);         // call rrdtool to do the biz.
>
>         dup2(oldstdout,1);      // restore stdout.
>         dup2(oldstderr,2);

You shouldn't close stderr, but redirect it somewhere, like to a file or
to /dev/null.
Is the command-string in 'buffer' properly terminated with a 0-byte?


Or *maybe*, as an alternative way to restore stderr, leave all that code
as is, but replace the line with "dup2(oldstderr,2);" by:

  close(2);
  dup(oldstderr);
  close(oldsterr);

which I copied from:
http://cvs.opensolaris.org/source/xref/usr/src/cmd/lp/filter/postscript/postio/ifdef.c


>> In a system() call, you can append " 2>$tmpfile" to the commandline.
>
> Yeah, I did think of that too - I'll have to try it again, but I
> think it produced the same result (browser hangs).

Do a test with "rrdtool graph - 2>/dev/null"
and also test "2>/dev/null rrdtool graph -"


Which shell do you use?

-- 
Grtz, Ruud

--
Unsubscribe mailto:rrd-developers-request at list.ee.ethz.ch?subject=unsubscribe
Help        mailto:rrd-developers-request at list.ee.ethz.ch?subject=help
Archive     http://lists.ee.ethz.ch/rrd-developers
WebAdmin    http://lists.ee.ethz.ch/lsg2.cgi



More information about the rrd-developers mailing list