Re: [Qemu-devel] [PATCH v2 3/5] qemu-img: avoid excessive BlockFragInfo line length

[Eric Blake]

On 02/06/2013 06:45 AM, Kevin Wolf wrote:
>>> Can you add a space before the '=' while touching this?
>>
>> Perhaps he can, but as this is user-visible output, and we don't yet
>> have a way to force JSON output to get at the same information,
>> arbitrarily changing the output format may break some existing user that
>> is scraping the output.  It would be nice if we had access to this
>> output information in a more stable format.
> 
> Are you aware of any existing user that makes use of this information?

Not particularly, which is why I'm okay if we modify the output.  I was
just making sure we were thinking about the issue.

> 
> We're going to add JSON output soon (possibly even before this series
> goes in) and scraping the output was never considered right for
> 'qemu-img check'. Also, so far this information only exists for QED
> images, which makes it rather unlikely to be relied on. I think
> modifying it is okay (if it wasn't, we would even have to think twice
> about adding new fields).

Adding the JSON output will go a long way towards giving us freedom to
rework the human output however we'd like.  But even if we don't get
JSON added in time for 1.4, I don't think it is the end of the world for
this particular use case.

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

signature.asc
Description: OpenPGP digital signature