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Date: Wed, 24 Jun 2009 22:47:30 +0100
From: Jamie Lokier <jamie@shareable.org>
Subject: Re: [Qemu-devel] [PATCH 01/11] QMP: Introduce specification file
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To: Filip Navara <filip.navara@gmail.com>
Cc: ehabkost@redhat.com, jan.kiszka@siemens.com, dlaor@redhat.com, qemu-devel@nongnu.org, Luiz Capitulino <lcapitulino@redhat.com>, Avi Kivity <avi@redhat.com>, Vincent Hanquez <tab@snarc.org>

Filip Navara wrote:
> > Looks to me like "works with libvirt and other management programs"
> > implies that you can use it from scripts, because many management
> > programs are, in fact, scripts.
> 
> If that was true then certainly a text/line-based protocol would make
> sense (possibly in addition to a simple RPC one, if desired). The
> thing I am worried about is that several corner cases are currently
> not defined in the proposed protocol and it introduces asynchronous
> events, which is actually harder to get right in shell scripts than
> the human protocol.

I generally agree, and to be honest the most useful API for scripts is
probably a "qemu-control [OPTIONS] CMD [ARGS...]" _program_ which they
can run, along the same lines as apachectl for Apache, smbcontrol for
Samba, ntpdc for NTPd, etc.

Such a program can be third party or not, once the monitor behaviour
is reliable for a program to use.

-- Jamie