From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39209) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eMadn-0003Wy-LS for qemu-devel@nongnu.org; Wed, 06 Dec 2017 09:25:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eMadj-0000fc-Nh for qemu-devel@nongnu.org; Wed, 06 Dec 2017 09:25:39 -0500 Date: Wed, 6 Dec 2017 14:25:13 +0000 From: "Daniel P. Berrange" Message-ID: <20171206142513.GD18296@redhat.com> Reply-To: "Daniel P. Berrange" References: <20171206115726.5237-1-berrange@redhat.com> <171741b3-39b8-7c37-8e07-4a9dd590e4c9@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <171741b3-39b8-7c37-8e07-4a9dd590e4c9@redhat.com> Subject: Re: [Qemu-devel] [PATCH] qemu-io: fix EOF Ctrl-D handling in qemu-io readline code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: qemu-devel@nongnu.org, Kevin Wolf , Stefan Hajnoczi , qemu-block@nongnu.org, Max Reitz On Wed, Dec 06, 2017 at 08:22:35AM -0600, Eric Blake wrote: > 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 > > Date: Thu Nov 14 11:54:17 2013 +0100 > > > > qemu-io: use readline.c > > > > Signed-off-by: Daniel P. Berrange > > --- > > 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? I was afraid someone was going to suggest doing that. I was being lazy by hardcoding Ctrl-D, but yes the real readline() library will honour the VEOF value. QEMU though is using a home-grown reimpl of readline... Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|