Clean-up, modernize, and add examples for $| and autoflush
#23147
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| STDOUT->autoflush(1); # Enable autoflush for STDOUT | ||
| STDERR->autoflush(0); # Disable autoflush for STDERR | ||
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| B<Warning:> C<$|> tells you only if you have asked Perl explicitly to |
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This isn't exactly what the previous comment was saying. It is saying that the channel may be buffered or not, if it is not buffered already then autoflush won't have any effect but it still defaults to 0.
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This was worded weird originally which is why I tried to clean it up. I'm not sure what the correct less-wordy verbiage should be?
$|tells you only if you have asked Perl explicitly to flush after each write. It is still possible the channel may be buffered by the system.
"Warning: External to Perl, the system may buffer a channel. If the system is not buffering a channel, then setting autoflush will not have any effect." ??
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I think rather than a warning, this statement is meant to be informational: the $|/autoflush setting always defaults to 0, and only indicates whether Perl flushes after each write, it does not indicate whether the channel is buffered by the system thus requiring flushing.
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Perhaps it would be better to have this information in the same place where it discusses the usual buffering of STDOUT since this is the property it's describing and not the autoflush behavior itself. And add that STDERR is typically unbuffered (but this may be system dependent, I am only familiar with Linux behavior).
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Also I was not being precise in saying autoflush won't have any effect on an unbuffered stream; Perl will still flush the handle after each write, it just won't make a difference because it wasn't being buffered anyway.
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The more I re-read this the more I think it was just informational. Personally I didn't think about the system buffering a channel, so knowing that setting autoflush in Perl may not always do what you want seems appropriate to me.
I think my wording here is ok-ish?
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The current wording in the commit is not useful information. The only reason to turn on autoflush is because the channel may be buffered.
Add some examples and clean up the wording for
$|and autoflush.