Re: Buffer contents well-defined after fgets() reaches EOF ?

On Sun 2/9/2025 5:06 PM, Andrey Tarasevich wrote:

On Sun 2/9/2025 3:52 PM, Lawrence D'Oliveiro wrote:

On Sat, 8 Feb 2025 23:12:44 -0800, Andrey Tarasevich wrote:
>

If `fgets` reads nothing (instant end-of-file), the entire buffer
remains untouched.

>
You mean, only a single null byte gets written.

 No. The buffer is not changed at all in such case.

... which actually raises an interesting quiz/puzzle/question:
   Under what circumstances `fgets` is expected to return an empty string? (I.e. set the [0] entry of the buffer to '\0' and return non-null)?
The only answer I can see right away is:
   When one calls it as `fgets(buffer, 1, file)`, i.e. asks it to read 0 characters.
This is under assumption that asking `fgets` to read 0 characters is supposed to prevent it from detecting end-of-file condition or I/O error condition. One can probably do some nitpicking at the current wording... but I believe the above is the intent.
--
Best regards,
Andrey