Re: stdbuf feature request - line buffering but for null-terminated data

[Kaz Kylheku]

On 2024-03-10 01:37, Pádraig Brady wrote:
> On 09/03/2024 16:30, Zachary Santer wrote:
>> 'stdbuf --output=L' will line-buffer the command's output stream.
>> Pretty useful, but that's looking for newlines. Filenames should be
>> passed between utilities in a null-terminated fashion, because the
>> null byte is the only byte that can't appear within one.
>>
>> If I want to buffer output data on null bytes, the closest I can get
>> is 'stdbuf --output=0', which doesn't buffer at all. This is pretty
>> inefficient.
>>
>> 0 means unbuffered, and Z is already taken for, I guess, zebibytes.
>> --output=N, then?
>>
>> Would this require a change to libc implementations, or is it possible now?
> 
> This does seem like useful functionality,
> but it would require support for libc implementations first.

Here is a lateral thinking kind of idea.

Let's assume that libc is not going to provide a null byte flushing mode any 
time soon.

What can be done inside utilities so that they can benefit from stdbuf
flushing control, without having to themselves control buffering?

What if there existed an alternative delimiting mode: a format where
the character strings are delimited by the two byte sequence \0\n.

This has several advantages:

1. It now works with line buffering.

2. Assuming \0 is just an invisible character consumed by terminals with no
   effect, this format can be dumped to a TTY where it turns into
   lines, as if the nulls were not there.

3. Portability: doesn't require a new buffering mode that would only
   be initially supported in Glibc, and likely never spread beyond
   a handful of freeware C libraries.