On Thu, Jun 18, 2015 at 10:41:56AM +0200, Pino Toscano wrote:
Hi,
On Thursday 18 June 2015 11:01:37 Cao jin wrote:
> > Speaking of this: you said that you have a colleague working on
> > btrfs-progs? What about suggesting to create some machine-parseable
> > output (csv, xml, yaml, json, whatever) so extracting the results of
> > btrfs tools is a lot more easy?
> >
>
> Yes, I forward your suggestion and consult him, the result is not
> surprised:( Here is what I learned from him:
> For the btrfs-progs cmds who output strings, the output are plain,
> don`t have patterns. Seen some guys who want a formatted output, they do
> a filter by themself, it not reasonable to ask btrfs-progs to output
> formatted strings.
This is exactly the issue here: every btrfs command has a totally
different formatting for its output. Just let him take a look at all
the commands implemented so far in libguestfs, you can easily spot
that:
- btrfs subvolume list
- btrfs subvolume show
- btrfs qgroup show
- btrfs balance status
- btrfs scrub status
- btrfs device stats
all have different custom parsers for each of their outputs.
Compare that to e.g. the -m parameter for parted, so it outputs fields
separated by semi-colon.
I have to agree with Pino T that btrfs-progs would be a lot better if
it had parseable output, like json/XML/etc, especially parseable
output that was stable over time.
Rich.
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