[PATCH v3] cmdline: update clear screen behavior

[Stephen Hemminger]

On Fri, 16 Jan 2026 18:42:56 +0300
Kerem Aksu <kerem.aksu at i2i-systems.com> wrote:

> Control+L should clear screen and redisplay prompt at the top
> line. DPDK rdline library will not change anything on the screen when
> fed with Control+L.  When prompt is lost after too many text written
> to the terminal, users will press Control+L to clear screen and put
> the prompt to the top line. This is expected behavior in bash(1) or
> applications that are using readline(3). Updated to behave as users
> expected.
> 
> Signed-off-by: Kerem Aksu <kerem.aksu at i2i-systems.com>
> ---
>  doc/guides/rel_notes/release_26_03.rst |  1 +
>  lib/cmdline/cmdline_rdline.c           | 29 ++++++++++++++++++++------
>  lib/cmdline/cmdline_vt100.h            |  1 +
>  3 files changed, 25 insertions(+), 6 deletions(-)

I was going to queue this to next-net.
But AI review sees some things that need to be addressed.
Do you want to resubmit with fixed release note, or I can fix that.


Errors: None.

Warnings:

    Release note entry is placed under "API Changes" but the public API signature is unchanged — this is a behavior change and may belong under a different section.
    Commit body could open with what the patch does rather than jumping into background.
    Pre-existing missing spaces around operators (i=0 ; i<rdl->prompt_size) in touched function — good opportunity to clean up.

Info:

    rdline_clear_screen() wrapper is only called once; could be inlined, but the named function improves readability at the call site. Fine either way.

Overall: Clean patch, good refactoring approach preserving the public API. No correctness issues.