Re: [Qemu-devel] [PATCH v2 03/15] char-pty: Drop "char device redirected to" message

[Paolo Bonzini]

On 11/04/19 16:52, Markus Armbruster wrote:
> char_pty_open() prints a "char device redirected to PTY_NAME (label
> LABEL)" message to the current monitor or else to stderr.  No other
> ChardevClass::open() prints anything on success.  Drop the message.
> 
> Cc: "Marc-André Lureau" <address@hidden>
> Cc: Paolo Bonzini <address@hidden>
> Signed-off-by: Markus Armbruster <address@hidden>
> Reviewed-by: Marc-André Lureau <address@hidden>
> ---
>  chardev/char-pty.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/chardev/char-pty.c b/chardev/char-pty.c
> index b034332edd..a48d3e5d20 100644
> --- a/chardev/char-pty.c
> +++ b/chardev/char-pty.c
> @@ -211,8 +211,6 @@ static void char_pty_open(Chardev *chr,
>      qemu_set_nonblock(master_fd);
>  
>      chr->filename = g_strdup_printf("pty:%s", pty_name);
> -    error_printf("char device redirected to %s (label %s)\n",
> -                 pty_name, chr->label);
>  
>      s = PTY_CHARDEV(chr);
>      s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd));

The reason for the message is that the char device is completely useless
until the user knows the /dev/pts/N path[1].  You can get it with "info
chardev" (aka query-chardev for QMP) but there's an interesting chicken
and egg problem if the pty is for your monitor...

Paolo

[1] once you know it, you can use the monitor's readline interface with
e.g. "socat STDIO,cfmakeraw FILE:/dev/pts/1"