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HTTP/2 200 cache-control: max-age=43200 server: Combust/Plack (Perl) vary: Accept-Encoding content-encoding: gzip content-length: 2278 content-type: text/html; charset=utf-8 last-modified: Sat, 11 Oct 2025 15:50:02 GMT traceparent: 540e3e9d54f5b9447e9cb32f2aeef5ae strict-transport-security: max-age=15768000 RE: Changing magic <> without changing core - nntp.perl.org

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RE: Changing magic <> without changing core

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From:

Ed Avis

Date:

July 28, 2008 06:56

Subject:

RE: Changing magic <> without changing core

Message ID:

7A5C308A1A3D554B8B8C0E331F7D2BB10ECCA9@wcl-exc.wcl.local

>readline override vs tieing a specific magic filehandle ?

I couldn't really say; a tied filehandle to me seems more normal and overriding readline more exotic and Acme-like. But that could be because I've never done it.

There is one wrinkle: from perlvar(1):

ARGV The special filehandle that iterates over command-line
filenames in @ARGV. Usually written as the null filehandle in
the angle operator "<>". Note that currently "ARGV" only has
its magical effect within the "<>" operator; elsewhere it is
just a plain filehandle corresponding to the last file opened
by "<>". In particular, passing "\*ARGV" as a parameter to a
function that expects a filehandle may not cause your function
to automatically read the contents of all the files in @ARGV.

I guess this is a symptom of it being implemented by overriding readline. A tied filehandle would not have this caveat. So readline would have better backwards compatibility.

I see no reason not to use a tied filehandle and get rid of this caveat, making both ARGV and MAGIC_ARGV work everywhere not just in <>. But I don't want to fight a holy war on two fronts against two different crusty misfeatures :-p. So whichever is easiest.

The $ARGV magic variable name currently works with <>. I think it would be overkill to set up a separate magic variable just for <<>> or whatever. You only use one or the other way of reading from files on the command line, never both in the same program. So $ARGV can work with both.

--
Ed Avis <eda@waniasset.com>

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