Re: [Qemu-devel] [PATCH] qemu-io: fix EOF Ctrl-D handling in qemu-io readline code

[Eric Blake <eblake@redhat.com>]

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On 12/06/2017 05:57 AM, Daniel P. Berrange wrote:
> qemu-io puts the TTY into non-canonical mode, which means no EOF processing is
> done and thus getchar() will never return the EOF constant. Instead we have to
> check for an explicit Ctrl-D, aka  0x4, to detect EOF and exit the qemu-io
> shell. This fixes the regression that prevented Ctrl-D from triggering an exit
> of qemu-io that has existed since readline was first added in
> 
>   commit 0cf17e181798063c3824c8200ba46f25f54faa1a
>   Author: Stefan Hajnoczi <stefanha@redhat.com>
>   Date:   Thu Nov 14 11:54:17 2013 +0100
> 
>     qemu-io: use readline.c
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  qemu-io.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

>      while (!line) {
>          int ch = getchar();
> -        if (ch == EOF) {
> +        /* In non-canon tty mode we get 0x4 (Ctrl-D), not the stdio "EOF"
> +         * constant */
> +        if (ch == 0x4) {

Should we instead be looking for a match against the current termios()
c_cc[VEOF] setting, in case the user prefers something other than ^D via
stty?  Does readline provide any functionality for automating this?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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