Re: "Text is read-only"... except it isn't... or shouldn't be

[Eli Zaretskii]

> Date: Tue, 14 May 2013 08:22:00 -0400
> From: ken <gebser@mousecar.com>
> CC: Eli Zaretskii <eliz@gnu.org>, help-gnu-emacs@gnu.org
> 
> [...] overly simplistic strategy for determining a file type merely
> by looking at the filename extension, especially when this can be
> more suitably and accurately and intelligently accomplished by
> determining a file's magic number as the Linux "file" utility does.

Emacs does look at the magic signature, see magic-mode-alist.