Re: [PATCH 00/13] usage cleanup part 1

["Rüdiger Meier" <sweet_f_a@gmx.de>]

On 06/26/2017 04:07 PM, Karel Zak wrote:
> On Mon, Jun 26, 2017 at 03:04:30PM +0200, Rüdiger Meier wrote:
>> On 06/22/2017 04:37 AM, Ruediger Meier wrote:
>>> From: Ruediger Meier <ruediger.meier@ga-group.nl>
>>>
>>> This is pull request #467 on github
>>> https://github.com/karelzak/util-linux/pull/467
>>
>>> The major goal is to avoid printing usage/help messages on stderr.
>>>
>>> This is the preparing first part of a bigger patch-set. There are
>>> some minor bug fixes and finally we add --help options to all our
>>> commands (just 5 commands were missing it).
>>>
>>> The next completing patch-set (part 2) will be more invasive but
>>> even more trivial.
>>
>> Thanks for merging.
>>
>> FYI I've PR'ed the second part on github only because it's almost
>> trivial but invasive.
>>     https://github.com/karelzak/util-linux/pull/471
> 
> Merged, thanks!
> 
> It seems we have many places with "not enough arguments" or "device no
> specified" or "bad usage". What about to create some inline function
> for these things?
> 
> static inline err_usage(int eval, char *msg)
> {
>      warnx(msg);
>      errtryhelp(eval);
> }
> 
> #define errnoargs(x)    err_usage(x, _("not enough arguments"))
> #define errnodevice(x)  err_usage(x, _("no device specified"))
> #define errbadusage(x)  err_usage(x, _("bad usage"))

> 
> Maybe it seems like over-engineering, but it's pretty common in the
> code and some consolidation to avoid creativity would be nice. The current
> solution requires
> 
>      if (argv < 2) {
>          warnx(_("not enough arguments")));
>          errtryhelp(EXIT_FAILURE);
>      }
> 
> I think
> 
>     if (argv < 2)
>         errnoargs(EXIT_FAILURE);
> 
> is shorter, seems better and provides control on the messages
> (errtryhelp() call, etc).
> 
> Comments?

I was already playing around with something like this

#define werrtryhelp(eval, s...) __extension__ ({ \
     warnx(s); \
     errtryhelp(eval); \
})

This would make things 1simple in about 100 cases, for example

   -       if (argc > 0) {
   -               warnx(_("%d too many arguments given"), argc);
   -               errtryhelp(EXIT_FAILURE);
   -       }
   +       if (argc > 0)
   +               werrtryhelp(EXIT_FAILURE, _("%d too many arguments given"), argc);


For the standard errors we would only need defines like:


#define ERR_MSG_NOARGS _("not enough arguments"))

   if (argv < 2)
       errtryhelp(EXIT_FAILURE, ERR_MSG_NOARGS);


Funny, I've had already deleted my werrtryhelp branch because I got
already tired of this cleanup. I just got it back from git-reflog
and safe it for later ;)

cu,
Rudi