Subject: Re: bug#79033: <<< unnecessary harmful substitution (EOF)

From: Stefan Monnier <[email-masked]>
Date: Thu, 17 Jul 2025 00:22:28 -0400

[ Please don't cross post to the bug address and to a mailing-list
  (e.g. [email-masked]).  ]

> I understand that typing 3 times '<' symbol forces auto substitution.

Actually not 3, only 2 (followed by space or dash, IIRC).

> I believe its a bug, it does not help me with anything, but wastes my
> time. it's VI level arcane magic no one needs.

As you have found out by now, there's a configuration variable that lets
you disable this "arcane magic".  But...

> Simple bash command I try to type in  - `somecommand <<< file.txt` becomes
> a nightmare.

The magic thingy does not trigger when I type the above command.
I vaguely remember we refined the magic which was triggered a bit too
eagerly some versions back, but even in Emacs-28.2 the above example you
provide does not trigger the magic to which you object, so I wonder if
you're using an even older version of Emacs or if you actually typed
something else.

        Stefan