Re: How to find the character breaking the file encoding?

[Óscar Fuentes]

Marcin Borkowski <mbork@mbork.pl> writes:

> I have a large UTF-8 file (about 1.5MB) to which I add stuff regularly.
> Recently, Emacs started saving it as a binary file.  I suspect I somehow
> inserted a non-UTF-8 sequence of bytes there.  Is there any way Emacs
> can help me finding it (other than me manually bisecting the file until
> I find the offending place)?

Try using M-x encode-coding-region ENTERT utf-8 ENTER

With some luck this will mark the buffer as modified because it replaces
unencodable content with blanks (IIRC). Then you can use M-x
diff-buffer-with-file to see the line that contains the problematic
sequence.