RE: [PATCH 0/4] btrfs-progs: Use common function to parse unit arguments

[Zhao Lei <zhaolei@cn.fujitsu.com>]

Hi, David Sterba

> -----Original Message-----
> From: David Sterba [mailto:dsterba@suse.cz]
> Sent: Saturday, August 29, 2015 1:24 AM
> To: Zhao Lei <zhaolei@cn.fujitsu.com>
> Cc: linux-btrfs@vger.kernel.org
> Subject: Re: [PATCH 0/4] btrfs-progs: Use common function to parse unit
> arguments
> 
> On Thu, Aug 27, 2015 at 09:38:19PM +0800, Zhao Lei wrote:
> > We are using separate code for parse unit mode in current code, result
> > is each command have different argument for unit mode:
> >
> >  # btrfs filesystem show --help
> >    ...
> >    --raw              raw numbers in bytes
> >    --human-readable   human friendly numbers, base 1024 (default)
> >    --iec              use 1024 as a base (KiB, MiB, GiB, TiB)
> >    --si               use 1000 as a base (kB, MB, GB, TB)
> >    --kbytes           show sizes in KiB, or kB with --si
> >    --mbytes           show sizes in MiB, or MB with --si
> >    --gbytes           show sizes in GiB, or GB with --si
> >    --tbytes           show sizes in TiB, or TB with --si
> >    ...
> >  #
> >  # btrfs filesystem df --help
> >    ...
> >    -b|--raw           raw numbers in bytes
> >    -h|--human-readable
> >                       human friendly numbers, base 1024 (default)
> >    -H                 human friendly numbers, base 1000
> >    --iec              use 1024 as a base (KiB, MiB, GiB, TiB)
> >    --si               use 1000 as a base (kB, MB, GB, TB)
> >    -k|--kbytes        show sizes in KiB, or kB with --si
> >    -m|--mbytes        show sizes in MiB, or MB with --si
> >    -g|--gbytes        show sizes in GiB, or GB with --si
> >    -t|--tbytes        show sizes in TiB, or TB with --si
> >    ...
> >  #
> >
> > This patchset introduce common function to parse arguments for setting
> > unit: get_unit_mode_from_arg()
> > and common help message for unit argument, to make every tool in btrfs
> > have same interface for setting unit.
> >
> > The merit are:
> > 1: Unify current each tool's arguments for unit
> > 2: Make tools in future easy to implement such argument
> > 3: Changes(enhancement) in common function have effect on all
> >    relative tools
> 
> I like this kind of unification and code simplification. However, the 'filesystem df'
> command keeps some option compatibility with the standalone 'df' commmand
> while the other btrfs commands use only long versions of the options. So we
> have to treat 'fi df' differently and not remove the existing short options. But
> otherwise looks good, thanks.

Thanks for explain why we use short option for df.
I'll send v2.

Thanks
Zhaolei