Re: [Qemu-devel] Guest-sync-delimited and sentinel issue

[Eric Blake <eblake@redhat.com>]

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On 03/16/2012 06:47 AM, Michal Privoznik wrote:
> Hi guys,
> 
> I was just implementing support for guest-sync-delimited into libvirt. My intent is to issue this command prior any other command to determine if GA is available or not. The big advantage is - it doesn't change the state of the guest so from libvirt POV it's harmless. The other big advantage is this sentinel byte 0xFF which is supposed to flush all unprocessed (and possibly stale) data from previous unsuccessful tries.
> 
> As written in documentation, this command will output sentinel byte to the guest agent socket. This works perfectly. However, it is advised in the very same documentation to prepend this command with the sentinel as well allowing GA parser flush. But this doesn't work for me completely. All I can get is:
> 
> $ echo -e "\xFF{\"execute\":\"guest-sync-delimited\", \"arguments\":{\"id\":1234}}" | nc -U /tmp/ga.sock | hexdump -C

side note - echo -e is non-portable; I would have written this as:

printf '\xff{"execute":"guest-sync-delimited", "arguments":{"id":1234}}'

-- 
Eric Blake   eblake@redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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