Re: Question: estimating size of a buffer when written to file?

[Daniel Martín]

Stephen Berman <stephen.berman@gmx.net> writes:

> On Wed, 8 Dec 2021 15:55:42 +0000 Qiantan Hong <qhong@mit.edu> wrote:
>
>>> Is (string-bytes (buffer-string)) not reliable?
>>> 
>>> Steve Berman
>> I’m not very familiar with different kinds of encoding,
>> but would some coding system result in final
>> writes longer than internal string-bytes?
>
> I'm afraid I don't know either.
>

Yes, if the coding system is not the UTF-8 variant used by Emacs
internally, the result won't be accurate for some scripts.  You need to
encode the contents of the buffer/string using the value of
buffer-file-coding-system, for example, and call string-bytes on it.