| Subject: | No information on binmode |
| Date: | Tue, 16 Oct 2007 16:50:27 +0200 |
| To: | bug-Tie-File [...] rt.cpan.org |
| From: | "yvon grall" <stabul [...] gmail.com> |
Hi !
I'd like to report a problem that I encountered with Tie::File under
Windows, using the "tying to an
already-opened filehandle" feature. On my opinion, it could be seen as a bug
on the Tie::File documentation.
It's up to you.
ENVIRONMENT:
Windows XP Pro sp1
Perl v5.8.8 built for MSWin32-x86-multi-thread (ActiveState)
Tie-File-0.96
SCRIPT:
Tying to an already-opened filehandle :
__CODE_BEGIN__
#!C:/Perl/bin/perl
use Fcntl;
use Tie::File;
sysopen($fh, 'file.log', O_RDWR | O_CREAT | O_TRUNC)
or die "cannot sysopen\n";
tie(@ties, 'Tie::File', $fh, mode => O_RDWR)
or die "cannot tie\n";
$ties[0] = "merde";
$ties[1] = "alors";
untie @ties;
close $fh;
__CODE_END__
PROBLEM:
When editing with vim (option ":set list" to see invisible characters),
instead of seeing two lines lihe this :
- first line : merde$
- second line : alors$
I read the following :
- first line : merde^M^Malors^M$
- second line : $
^M is the carriage-return character (ASCII code 0x0D - "\r" in perl -)
$ is the end-of-line character(s) (in this case, for Windows, 2 characters :
0x0D 0x0A - "\r\n" in perl -)
Note: the same code works fine under Linux.
SOLUTION (WORKAROUND ?):
After a few hours of debug ( I'm far - so far - to be a perl expert :-( ), I
found the solution... in the Tie/File.pm
module, written as a comment, at line 93 :
$fh = $file; # setting binmode is the user's problem
So, indeed, I added the line "binmode $fh;" in my script between the sysopen
and the tie calls, and
the problem was resolved.
Solution or Workaround ?: it's allright now for me. But, is it a perfect
solution ? I mean, the script works here
with a text file. It is surprising that shifting to the binmode resolves the
problem. Isn't it ?
CHANGE REQUEST ON DOCUMENTATION:
In the "Tying to an already-opened filehandle" chapter, it would ne nice to
talk about the binmode recommandation
for the Windows environment.
bye,
Stabul
P.S.: while debugging, I also noticed that a semi-colon misses at line 92
(without any consequence; strange, isn't it ?)
P.P.S.: The official version of Tie-File (0.96) doesn't compile OK on Win32
platform (it's already reported in CPAN).
The 0.97 (or 0.98) version of Dan Kogan (
http://www.dan.co.jp/~dankogai/cpan/<http://www.dan.co.jp/%7Edankogai/cpan/>)
compiles without errors. Why
isn't it the official version of Tie::File under CPAN ?