Re: Changing the charset

On 2026-05-19 01:23, Stefan G. Weichinger via samba wrote:

>
> I recently had an issue where a user couldn't correctly store an email 
> out of his Outlook on an windows 11 PC to samba.
>
> Something around illegal characters (sry, I don't have the message at 
> hand right now).
>
> The samba is 4.22.8 on Debian-13 and it has been historically upgraded 
> over years ...
>
> The former admin configured:
>
>     dos charset = CP850
>     unix charset = iso8859-15
>
> And I kept it that way because I didn't want to break things (and it 
> wasn't a problem so far ...).
>
> Is changing this to UTF-8 problematic?
> Does that break filenames or the displayed names? 

With all due respect to the expert and unendingly helpful Rowland Penny, 
changing a charset from iso8859-15 to utf-8 might very well invalidate 
some stored filenames and configuration strings.

ISO8859-15[1] is a character set for Western European languages written 
using the Latin script. Every character occupies one byte.
UTF-8[2] is a way of storing Unicode character values in 1, 2, 3, or 
4-byte sequences.

It is correct that every character in ISO8859-15 can be represented in 
UTF-8. It is also correct that every character in ISO8859-15 which has a 
byte value of 127 or less is represented in UTF-8 by a single byte with 
the same byte value.

However, those characters in ISO8859-15 which have a byte value of 128 
or greater are represented by two-byte sequences in UTF-8. So, text data 
— for instance a file name — which was stored as bytes with values of 
128 or greater, encoded in ISO8859-15, will not be legible if read back 
as UTF-8.

I do not know how Samba uses those admin settings of "dos charset" and 
"unix charset". I do not know how it affects the interpretation of byte 
values in configuration strings or filenames. Thus I can't advise you 
what else you need to convert when you change these settings.  For what 
it's worth, I have a suspicion that those settings may affect how the 
byte sequences of filenames are interpreted, and if your filenames 
include accented Latin characters and such, those filenames will need to 
be converted from ISO8859-15 to UTF-8 form separately from Samba. Arnaud 
Florent's suggestion of `convmv` to convert filenames from ISO8859-15 
encoding to UTF-8 encoding seems like it would be helpful.

> We can't backup/restore all the files or so .. so I have to research 
> how to maybe solve this.
>
> Thanks for any advice! 

Best regards,
       —Jim DeLaHunt, who knows little about Samba, but a lot about 
Unicode and UTF-8.

[1] <https://en.wikipedia.org/wiki/ISO/IEC_8859-15>
[2] <https://en.wikipedia.org/wiki/UTF-8>


-- 
.   --Jim DeLaHunt     http://blog.jdlh.com/ (http://jdlh.com/)
       Vancouver, B.C., Canada


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