Re: [ptxdist] [PATCH] rootfs: resize terminal on login

[Michael Olbrich <m.olbrich@pengutronix.de>]

On Tue, Aug 22, 2023 at 12:02:53PM +0200, Roland Hieber wrote:
> When logging in over a serial line, the default terminal size of 80x24
> is assumed by default, which makes e.g. systemctl output scroll sideways
> unnecessarily when the serial connection is running inside a larger
> terminal on the host. Therefore the first thing I do after login is
> usually to call 'resize' (which is enabled by default via busybox) to
> determine the real size of the terminal and set the COLUMNS and LINES
> environment variables accordingly.
> 
> For the sake of convenience, do that automatically when starting a login
> shell as it has no downsides. Also wrap it inside an 'eval' call, partly
> to silence resize's output, and partly to support shells that cannot
> determine the COLUMNS and LINES variables by themselves and rely on it
> being set explicitely.
> 
> Signed-off-by: Roland Hieber <rhi@pengutronix.de>
> ---
>  projectroot/etc/profile | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/projectroot/etc/profile b/projectroot/etc/profile
> index 259113d3330d..f8c03b35cd11 100644
> --- a/projectroot/etc/profile
> +++ b/projectroot/etc/profile
> @@ -7,6 +7,9 @@ if [ "$TERM" != "linux" ]; then
>          stty erase ^H
>  fi
>  
> +# don't only assume a 80x24 terminal
> +eval $(resize)
> +

Hmm, I'm not sure if this is something we want to do unconditionally. It's
certainly not needed for ssh logins (or telnet for that matter).

Maybe something like this (untested):

case "$(tty 2>/dev/null)"; in
/dev/pts/*)
	;;
*)
	eval $(resize) ;;
esac

Michael

>  # source this file for subsequent shells, too
>  # (will also be sourced for init-shell)
>  export ENV=/etc/profile.environment
> -- 
> 2.39.2
> 
> 
> 

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