Re: [PATCH] btrfs-progs: subvolume: outputs message only when operation succeeds

[Hugo Mills <hugo@carfax.org.uk>]

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On Mon, Sep 25, 2017 at 03:46:15PM +0800, Qu Wenruo wrote:
> 
> 
> On 2017年09月25日 15:42, Marat Khalili wrote:
> >On 25/09/17 10:30, Nikolay Borisov wrote:
> >>On 19.09.2017 10:41, Misono, Tomohiro wrote:
> >>>"btrfs subvolume create/delete" outputs the message of "Create/Delete
> >>>subvolume ..." even when an operation fails.
> >>>Since it is confusing, let's outputs the message only when an
> >>>operation succeeds.
> >>Please change the verb to past tense, more strongly signaling success -
> >>i.e. "Created subvolume"
> >What about recalling some UNIX standards and returning to NOT
> >outputting any message when operation succeeds? My scripts are
> >full of grep -v calls after each btrfs command, and this sucks
> >(and I don't think I'm alone in this situation).
> 
> Isn't the correct way to catch the return value instead of grepping
> the output?

   It is, but if, for example, you're using the command in a cron
script which is expected to work, you don't want it producing output
because then you get a mail every time the script runs. So you have to
grep -v on the "success" output to make the successful script silent.

> If it's some command not returning value properly, would you please
> report it as a bug so we can fix it.

   It's not the return value that's problematic (although those used
to be a real mess). It's the fact that a successful run of the command
produces noise on stdout, which most commands don't.

   Hugo.
 
> Thanks,
> Qu
> 
> >If you change the message a lot of scripts will have to be
> >changed, at least make it worth it.
> >
> >  --
> >
> >With Best Regards,
> >Marat Khaliili
> >

-- 
Hugo Mills             | If you see something, say nothing and drink to
hugo@... carfax.org.uk | forget
http://carfax.org.uk/  |
PGP: E2AB1DE4          |                                 Welcome to Night Vale

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