Perl binmode problem on text mount

[Christopher Faylor]

On Thu, Nov 04, 2004 at 12:28:33PM -0500, Igor Pechtchanski wrote:
>On Thu, 4 Nov 2004, Christopher Faylor wrote:
>
>> On Wed, Nov 03, 2004 at 09:21:50PM -0800, Earl Chew wrote:
>> >Igor Pechtchanski wrote:
>> >>On Wed, 3 Nov 2004, Earl Chew wrote:
>> >>
>> >>>This code used to work on Perl 5.6.1-2 on Cygwin 1.3.10.
>> >>>
>> >>>I've now moved to Perl 5.8.5-3 on Cygwin 1.5.11.
>> >>>
>> >>>Here is the Perl program:
>> >>>
>> >>>	binmode STDOUT;
>> >>>	print "Hello\n";
>> >>>
>> >>>1. Output to file on text mount
>> >>>
>> >>>	perl foo.pl > foo.txt ; od -c foo.txt
>> >>>
>> >>>	0000000  H e l l o \r \n	# Perl 5.8.5-3 Cygwin 1.5.11
>> >>>	0000000  H e l l o \n		# Perl 5.6.1-2 Cygwin 1.3.10
>> >[ .. snip .. ]
>> >>This is expected behavior.  Unless you use raw writes (as "cat" does), the
>> >>mode of the file (text or binary) is determined *by the program that opens
>> >>the file*.  In the above case, the program is not perl, it's your shell.
>> >
>> >I think you're telling me that "binmode STDOUT" has no effect. I find
>> >this counterintuitive.
>> >
>> >Without "binmode STDOUT", I can see how your explanation would work.
>>
>> AFAIK, binmode STDOUT should work fine.  It should eventually translate
>> to the setmode call.
>
>Do you mean the "set_flags" call?

No.

>> Since setmode takes an fd argument it obviously should affect the mode
>> of the file being read or written regardless of how it was originally
>> opened.
>
>I used the command-line version of the above script:
>
>strace -o bmode.strace perl -e 'binmode STDOUT;print "Hello\n"' > foo.txt
>
>bmode.strace was only ~350 lines, and it seems to show that the mode of fd
>1 is set to text based on the mount info, and never reset to binary
>afterwards.  fhandler_base::write reports a text write.  So it does look
>like "binmode STDOUT" doesn't work...  What am I missing?

You are missing the fact that the OP was reporting a real bug, apparently.

cgf

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