Re: [PATCH v10 1/2] cmdline: handle EOF in cmdline_poll

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 1/30/2023 8:09 PM, Stephen Hemminger wrote:
> If end of file is reached on input, then cmdline_read_char()
> will return 0. The problem is that cmdline_poll() was not checking
> for this and would continue and not return the status.
> 
> Fixes: 9251cd97a6be ("cmdline: add internal wrappers for character input")
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> ---
>  lib/cmdline/cmdline.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/cmdline/cmdline.c b/lib/cmdline/cmdline.c
> index e1009ba4c413..de41406d61e0 100644
> --- a/lib/cmdline/cmdline.c
> +++ b/lib/cmdline/cmdline.c
> @@ -194,7 +194,7 @@ cmdline_poll(struct cmdline *cl)
>  	else if (status > 0) {
>  		c = -1;
>  		read_status = cmdline_read_char(cl, &c);
> -		if (read_status < 0)
> +		if (read_status <= 0)
>  			return read_status;

According API doc it will be wrong to return '0', which imply 'RDLINE_INIT'.

But function may return any negative value on error, what about to get
eof as and error case:

if (read_status < 0)
	return read_status;
else if (read_status == 0)
	return -EIO;

With this 'cmdline_poll()' can be used in testpmd as it is used in v9 of
this patch:
while (f_quit == 0 && cl_quit == 0) {
	if (cmdline_poll(cl) < 0)
		break;
}



But still I guess this is an ABI break because of API behavior change.