Subject: Re: bug#10253: mention +FORMAT in ls time style reminder help blurb

From: Eric Blake <[email-masked]>
Date: Fri, 09 Dec 2011 14:30:14 -0700

On 12/09/2011 12:22 PM, Jim Meyering wrote:
> [email-masked] wrote:
>> $ ls -t1 --time-style=%c -og
>> ls: invalid argument `%c' for `time style'
>> Valid arguments are:
>>   - `full-iso'
>>   - `long-iso'
>>   - `iso'
>>   - `locale'     <-------------you forgot to also mention "+FORMAT"
>> Try `ls --help' for more information.
>> $ ls -t1 --time-style=+%c -og
> 
> Thanks for the report.
> However, that doesn't lend itself well to a clean fix, since +FORMAT
> is not a literal string option argument like the others, and currently
> that diagnostic is generated automatically based on the list of literal strings.

I agree that listing `+FORMAT' doesn't fit the pattern.  But maybe we
can make it obvious that there is a non-literal possibility, as well as
also mentioning the posix- prefix already covered by 'ls --help':

Valid arguments are:
  - `[posix-]full-iso'
  - `[posix-]long-iso'
  - `[posix-]iso'
  - `[posix-]locale'
  - `+' followed by formatting directives
Try `ls --help' for more information.

Also, I noticed that 'ls --help' uses FORMAT in the text for
--time-style, but doesn't define FORMAT anywhere else; we probably ought
to have a one-line sentence at the bottom, after the paragraph on SIZE,
stating:

See `date --help' for valid directives that may appear in FORMAT.

-- 
Eric Blake   [email-masked]    +1-919-301-3266
Libvirt virtualization library http://libvirt.org