Re: [PATCH v4 2/2] testpmd: enable interrupt in interactive mode

[Olivier Matz <olivier.matz@6wind.com>]

On Wed, Mar 15, 2023 at 10:31:32AM -0700, Stephen Hemminger wrote:
> The setting in terminal handling for both Unix style and
> Windows was not ensuring that Ctrl-C character would
> cause interrupt.
> 
> This is a first release bug. Testpmd interactive mode has
> always disabled control-c handling on Linux.

This was a design choice, not a bug. This design choice is discussable
today (at that time, dpdk was also running in baremetal without signals
or interrupt). The idea was to behave like a shell, i.e. ctrl-c just
clears the current line.

We may want to change this behavior (I remember an old discussion where
Bruce stated that he would prefer ctrl-c to kill the program), but it
will have an impact on all cmdline users, so to me it has to be
announced.


> 
> Fixes: af75078fece3 ("first public release")
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> ---
>  lib/cmdline/cmdline_os_unix.c    | 3 ++-
>  lib/cmdline/cmdline_os_windows.c | 4 ++--
>  2 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/cmdline/cmdline_os_unix.c b/lib/cmdline/cmdline_os_unix.c
> index 5f9839a15f98..356c5b3f3ca2 100644
> --- a/lib/cmdline/cmdline_os_unix.c
> +++ b/lib/cmdline/cmdline_os_unix.c
> @@ -16,7 +16,8 @@ terminal_adjust(struct cmdline *cl)
>  	tcgetattr(0, &cl->oldterm);
>  
>  	memcpy(&term, &cl->oldterm, sizeof(term));
> -	term.c_lflag &= ~(ICANON | ECHO | ISIG);
> +	term.c_lflag &= ~(ICANON | ECHO);
> +	term.c_lflag |= ISIG;
>  	tcsetattr(0, TCSANOW, &term);
>  
>  	setbuf(stdin, NULL);
> diff --git a/lib/cmdline/cmdline_os_windows.c b/lib/cmdline/cmdline_os_windows.c
> index 80863bfc8a00..8cff3b175747 100644
> --- a/lib/cmdline/cmdline_os_windows.c
> +++ b/lib/cmdline/cmdline_os_windows.c
> @@ -32,10 +32,10 @@ terminal_adjust(struct cmdline *cl)
>  		mode &= ~(
>  			ENABLE_LINE_INPUT |      /* no line buffering */
>  			ENABLE_ECHO_INPUT |      /* no echo */
> -			ENABLE_PROCESSED_INPUT | /* pass Ctrl+C to program */
>  			ENABLE_MOUSE_INPUT |     /* no mouse events */
>  			ENABLE_WINDOW_INPUT);    /* no window resize events */
> -		mode |= ENABLE_VIRTUAL_TERMINAL_INPUT;
> +		mode |= ENABLE_VIRTUAL_TERMINAL_INPUT |
> +			ENABLE_PROCESSED_INPUT; /* Ctrl C processed by the system */
>  		SetConsoleMode(handle, mode);
>  	}
>  
> -- 
> 2.39.2
>