Re: [PATCH] slcanpty

[Oliver Hartkopp <socketcan@hartkopp.net>]

Hi Janusz,

thanks for the patch.

I changed it in the way the perror() is only called on negative return values.

Please check it out for a test.

Best regards,
Oliver

On 07.06.2013 15:40, janusz.uzycki@elproma.com.pl wrote:
> Hi Oliver.
> 
> I've tested the following case:
> modprobe vcan
> ip link add dev vcan0 type vcan
> #ip link set vcan0 up type can bitrate 125000
> ip link set vcan0 up
> socat PTY,link=/tmp/a -
> cgdb --args ./slcanpty /tmp/a vcan0
> 
> If socat killed slcanpty should finish instead of crazy loop (select always
> returns).
> Here is proposal of very little patch:
> From a708491ea49e170ac1d36148e75b7b6c6f07b6fd Mon Sep 17 00:00:00 2001
> From: Janusz Uzycki <j.uzycki@elproma.com.pl>
> Date: Fri, 7 Jun 2013 15:25:39 +0200
> Subject: slcanpty: detect that master PTY descriptor closed
> 
> 
> Signed-off-by: Janusz Uzycki <j.uzycki@elproma.com.pl>
> ---
>  slcanpty.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/slcanpty.c b/slcanpty.c
> index f3628b9..061c1ab 100644
> --- a/slcanpty.c
> +++ b/slcanpty.c
> @@ -75,7 +75,7 @@ int pty2can(int pty, int socket, struct can_filter *fi,
>         int tmp, i;
> 
>         nbytes = read(pty, &buf, sizeof(buf)-1);
> -       if (nbytes < 0) {
> +       if (nbytes <= 0) { /* 0 means that master PTY descriptor has been
> closed */
>                 perror("read pty");
>                 return 1;
>         }
> -- 
> 1.7.11.3
> 
> best regards
> Janusz
>