Re: [Qemu-devel] [PATCH v2] qemu-io: fix EOF Ctrl-D handling in qemu-io readline code

["Daniel P. Berrangé" <berrange@redhat.com>]

Re-ping.

On Thu, Jan 25, 2018 at 05:05:01PM +0000, Daniel P. Berrangé wrote:
> ping, does any block maintainer want to queue this one ?
> 
> On Fri, Dec 08, 2017 at 01:34:16PM +0000, 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
> > query the TTY attributes to determine the configured EOF character (usually
> > Ctrl-D / 0x4), and then explicitly check for that value. 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>
> > ---
> > Changed in v2:
> > 
> >   - Query termios settings for EOF character
> > 
> >  qemu-io.c | 26 +++++++++++++++++++++++++-
> >  1 file changed, 25 insertions(+), 1 deletion(-)
> > 
> > diff --git a/qemu-io.c b/qemu-io.c
> > index c70bde3eb1..fa4972d734 100644
> > --- a/qemu-io.c
> > +++ b/qemu-io.c
> > @@ -10,6 +10,9 @@
> >  #include "qemu/osdep.h"
> >  #include <getopt.h>
> >  #include <libgen.h>
> > +#ifndef _WIN32
> > +#include <termios.h>
> > +#endif
> >  
> >  #include "qapi/error.h"
> >  #include "qemu-io.h"
> > @@ -41,6 +44,26 @@ static bool imageOpts;
> >  
> >  static ReadLineState *readline_state;
> >  
> > +static int ttyEOF;
> > +
> > +static int get_eof_char(void)
> > +{
> > +#ifdef _WIN32
> > +    return 0x4; /* Ctrl-D */
> > +#else
> > +    struct termios tty;
> > +    if (tcgetattr(STDIN_FILENO, &tty) != 0) {
> > +        if (errno == ENOTTY) {
> > +            return 0x0; /* just expect read() == 0 */
> > +        } else {
> > +            return 0x4; /* Ctrl-D */
> > +        }
> > +    }
> > +
> > +    return tty.c_cc[VEOF];
> > +#endif
> > +}
> > +
> >  static int close_f(BlockBackend *blk, int argc, char **argv)
> >  {
> >      blk_unref(qemuio_blk);
> > @@ -322,7 +345,7 @@ static char *fetchline_readline(void)
> >      readline_start(readline_state, get_prompt(), 0, readline_func, &line);
> >      while (!line) {
> >          int ch = getchar();
> > -        if (ch == EOF) {
> > +        if (ttyEOF != 0x0 && ch == ttyEOF) {
> >              break;
> >          }
> >          readline_handle_byte(readline_state, ch);
> > @@ -592,6 +615,7 @@ int main(int argc, char **argv)
> >      qemuio_add_command(&close_cmd);
> >  
> >      if (isatty(STDIN_FILENO)) {
> > +        ttyEOF = get_eof_char();
> >          readline_state = readline_init(readline_printf_func,
> >                                         readline_flush_func,
> >                                         NULL,
> > -- 
> > 2.14.3
> > 
> 
> Regards,
> Daniel
> -- 
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> 

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
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