[oak perl] Re: [sf-perl] print Dumper \$|;

[Belden Lyman]

Paul Makepeace wrote:
> On Wed, Jan 15, 2003 at 04:30:44PM -0800, Belden Lyman wrote:
> 
>>Flush pipes, print $|:
>>
>>    % perl -MData::Dumper -e '$|++; print Dumper \$|'
>>    $VAR1 = \'1';
>>
>>Okay, I believe that.
>>
>>Clog pipes, print $|:
>>
>>    % perl -MData::Dumper -e '$|--; print Dumper \$|'
>>    $VAR1 = \'1';
>>
>>Huh? Same value? That can't be right though, because
> 
> 
> This is a known perl oddity, and often used by golfers and obfuscators
> as a toggler.
> 
> $ perl -le 'print "p",--$|,"ng!" for 1..4'
> p1ng!
> p0ng!
> p1ng!
> p0ng!
> $
> 
> Paul
> 


Sure, I know that. :)

My intended question was, "How come Data::Dumper thinks $|-- has the
same value as $|++ ?"

Your example is better at showing that $| obviously is changing value.
But it doesn't explain why printing $| using Data::Dumper always gives
back \'1', seemingly without regard to the actual value of $| at the
time.

I suspect the problem is that within the context of Data::Dumper, $|
is always flushed, but I'm grasping here.

Belden