Re: user sees \xxx but is thwarted from searching for them

["Eli Zaretskii" <eliz@is.elta.co.il>]

> From: Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai =?iso-8859-1?q?Gro=DFjohann?=)
> Newsgroups: gnu.emacs.bug
> Date: Tue, 16 Apr 2002 12:55:12 +0200
> 
> eliz@is.elta.co.il (Eli Zaretskii) writes:
> 
> > `M-: (skip-chars-forward "\000-\177") RET' will do.  
> 
> This command finds \x7f, too, even if it is displayed without \ on
> screen.  I presume it will also find a lot of other nonascii
> characters.

More accurately, if finds _any_ non-ASCII character.  That's what it
is supposed to do.

> Suppose you have a file which is mostly in the foo encoding, but
> contains some bytes that are invalid in that encoding.  I think this
> is the situation Dan is talking about.  He wants to find the invalid
> bytes, IIUC.

Perhaps I don't understand the original request, but if I do, it is
very hard to do that (AFAIK) without knowing what--i.e. which
character sets--are you looking for.  Recall that, once the file is
visited by a buffer, there are no bytes, just characters.  What you
want is to find characters that don't belong to some set of
characters, without actually telling Emacs what are those ``good''
sets.  This might be relatively easy if your buffer holds characters
from a single charset, but I doubt that Emacs users can be charged
with the burden of knowing about such technicalities.

> Maybe it helps to try to save the buffer to a file, and let Emacs
> complain about the character that couldn't be encoded using the
> current coding system.  But I'm not sure if that does the trick,
> though.

It doesn't; see my other mail.