Re: Multiple encodings in one file

[Stefan Monnier]

>> Thank you for the time. What you said gives me some hope but I have
>> a follow-up question. If I visit a file literally, make a change, and
>> save it, the file seems to be different only where I changed it. Is
>> that true?
>
> If you save it while binding coding-system-to-write to no-conversion,
> yes.  IOW, you need to disable encoding while saving.

Also, if you open the file as a if it was all utf-8, then the utf-8
parts of the file should look just fine (and the MARC-8 parts may look
screwy) and if you edit it and save the result it *should* result in
a valid file where only the part your changed was modified.

>> If so, then does the following seem reasonable.
>> 
>> 1 Find a file literally.
>> 2 The user will accept that some characters will show octal codes or
>>   something similar.
>> 3 Edit the records where understandable and possible. 
>> 4 Save file.

For a quick&dirty solution that should work as long as you're doing
limited changes and only in parts that are mostly ASCII.

If you're designing a major mode, maybe a better approach would look
like: read the file literally (i.e. as bytes) and treat it as a kind of
directory or archive (think tar-mode, dired, archive-mode, Rmail) so
only show a summary of the contents, then let the users "open" a record
which is then extracted (and decoded) into another buffer.


        Stefan