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Re: Perl binmode problems when redirecting to text mounts
On Mon, 22 Aug 2005, Gerrit P. Haase wrote:
> Igor Pechtchanski wrote:
>
> > On Sun, 21 Aug 2005, Igor Pechtchanski wrote:
> >
> >
> > > I'm trying to make sure our perl program works with text mounts. In the
> > > course of the testing, one weird problem cropped up: binmode seems to
> > > have no effect on STDOUT when redirecting to a file on a text mount.
> > >
> > > The following consistently reproduces the problem for me:
> > >
> > > $ mount -m | grep text
> > > mount -f -u -t "c:/cygwin/tmp/text" "/tmp/text"
> > > $ cd /tmp/text
> > > $ /usr/bin/perl -e 'binmode(STDOUT);print "\n"' > PT
> > > $ od -c PT
> > > 0000000 \r \n
> > > 0000002
> > > $
> > >
> > > I've tried various combinations of ":raw", ":perlio", etc, both directly
> > > and through the PERLIO variable, with no success. The strace output
> > > (available upon request) seems to show that the handle is successfully
> > > set to binary mode, but that the write still happens in text mode.
> > >
> > > Can anyone else reproduce this? Is there a way I can force binary mode
> > > on STDOUT in Perl?
> >
> >
> > On second thought, this probably has to do with *how* Perl sets binmode on
> > STDOUT. The shells (I tried ash, bash, tcsh) don't seem to honor it.
> >
> > BTW, the code I used is the same as that in /usr/bin/GET.pl and
> > /usr/bin/piconv (both break in the same way on redirection to files on
> > text mounts).
> >
> > I know the shells can honor the O_BINARY specifier on STDOUT, since "cat"
> > uses this (via setmode(1, O_BINARY)). There must be something that Perl
> > is doing differently. Any ideas?
>
> I believe that this was discussed before, evtually a bug report was already
> filed. I think the problem is the redirection, here is the
> shell involved. Please search the archives (and send me a link when
> you have found it).
Here's the thread, with a nearly identical subject:
<http://cygwin.com/ml/cygwin/2004-11/msg00131.html>. The conclusion was
that someone has to report this as a perl bug. Apparently, nobody did.
Igor
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