It doesn't work for me with any of 5.8.4, 5.10.0, 5.10.1, 5.12.2 and 5.12.3 (those are the ones I have available for testing here). And IIRC, it never worked with any vanilla build of perl. Maybe your Slackware 5.10.0 had a specific patch applied?

I dimly recall there was a thread here a couple of years ago that discussed the issue — but I can't find it right now... (maybe someone else will) .

Upd: I think this is what I remembered: Clash between IO layers and "in memory" files?.

In reply to Re: Perl 5.12: layers and opening scalars as file handles by Eliya
in thread Perl 5.12: layers and opening scalars as file handles by afoken

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