Hi Nikola,

On Sun, Aug 03, 2025 at 06:50:49PM +0300, Никола Константинов Кралев wrote:

Hello,

with some manual testing, when a large optional-arg is placed I can
see that the byte count limit is not 255/127 characters (since/before
Linux 5.1) after the first two bytes of the file being "#!" these, but
the actual count limit is 255 characters starting at file offset zero.
So, technically, the largest possible full path that can be placed as
the interpreter is (255 - strlen("#!")) bytes long.

Would you mind showing a test that demonstrates this?

Meaning that, the execve(2) man page https://www.man7.org/linux/man-pages/man2/execve.2.html should be corrected to something like:

The kernel imposes a maximum length on the text that follows the
"#!" characters at the start of a script; characters beyond the
limit are ignored. Before Linux 5.1, the limit is 127 characters including the "#!" characters at the start.
Since Linux 5.1, the limit is 255 characters including the "#!" characters at the start.

Sounds good.

Should I manually send a pull request and edit the plaintext man page
from its git repository? Or will the man page maintainers correct that?

Yes, you're welcome to send a patch!  Please have a look at
<https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING>
<https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING.d>


Have a lovely day!
Alex

-- 
<https://www.alejandro-colomar.es/>