Re: [Qemu-block] interactive qemu-img

[Programmingkid]

> On Jul 30, 2018, at 6:14 PM, Nir Soffer <address@hidden> wrote:
> 
> On Mon, Jul 30, 2018 at 11:09 PM Eric Blake <address@hidden> wrote:
> On 07/30/2018 02:54 PM, Nir Soffer wrote:
> 
> >>> $ qemu-img
> >>> qemu-img: Not enough arguments
> >>> Try 'qemu-img --help' for more information
> > 
> > 
> > This is not user friendly, but unfortunately very common.
> > It can be improved by treating no arguments as --help, like git.
> 
> I somewhat disagree that git is a good example.  If '--help' occupies 
> more than about 25 lines (a screenful on some default terminal sizes), 
> the mere fact that you have to scroll to read it makes it less helpful 
> than a 2-liner statement that lets you know "I couldn't do anything 
> useful with your botched command line, please read the documentation and 
> try again".  'git' behaving as 'git --help' outputs 42 lines, which 
> fails my 'one screenful' test; and 'qemu-img --help' at 104 lines is 
> definitely too verbose to be the default behavior when --help is not given.
> 
> /me Wow - I can't believe I'm actually about to use this as an example, but:
> 
> 'cvs' and 'cvs --help' is just 13 lines (except to stderr, when it 
> should have been stdout), and gives enough hints on how to get more 
> specific help on a particular topic.  Great for the plain 'cvs' case; a 
> bit more debatable on 'cvs --help' (the fact that you have to ask for 
> help twice: once for the summary, again for the specific help, gets 
> tedious).
> 
> At any rate, getting command-line tools to have user-friendly behavior 
> when insufficient arguments are supplied is an artform, and you'll find 
> lots of bikeshed colors out there.
> 
> And regardless of any opinions I've expressed above, this thread does 
> point out that 104 lines for 'qemu-img --help' is long, and anything we 
> can do to make that easier to digest may still be worthwhile.
> 
> I agree that git help is too long, and falling back to --help without 
> improving
> qemu-img help is not very useful.
> 
> What we need is something like:
> 
> $ qemu-img 
> 
> Commands:
>   amend       description...
>   bench       description...
>   check       description...
>   commit      description...
>   compare     description...
>   convert     description...
>   create      description...
>   dd          description...
>   info        description...
>   map         description...
>   measure     description...
>   snapshot    description...
>   rebase      description...
>   resize      description...
>   
> This fits in a terminal, and we have space for additional tips or common
> command line options.

This looks actually readable. I like the idea.