[Aptitude-devel] Bug#815690: aptitude: regression in version 0.7.6 wrt. cli search display through pipes

[Norbert Kiesel]

Actually I started to like the perl post-processing, so I will simply close
my bug report although I'm still not understanding why the width in the
format does not work in piped context.

For the record, here is my updated bash function I use to list new packages
function new-packages {
    t=$(mktemp)
    trap "rm -f $t" RETURN
    aptitude -F '%p %d' search '~N' | perl -ne 'printf("%-40s - %s\n",
/(\S+) (.+)/)' > $t
    if [[ -s $t ]] ; then
        less $t
        read -n1 -p 'aptitude forget-new [ycN]? ' forget
        [[ $forget =~ [cC] ]] && ( echo; cat $t )
        [[ $forget =~ [yY] ]] && aptitude forget-new
    fi
}


On Tue, Feb 23, 2016 at 6:34 PM, Norbert Kiesel <nkiesel at gmail.com> wrote:

> Hi Manuel,
>
> my goal was pretty simply: I wanted the output be nicely aligned even when
> it's piped.  When I tried that using -F I thought that -F is just ignored.
> However, as you have shown that is not the case.
>
> Nevertheless, it seems that setting the width of columns does not work as
> I expected:
> # aptitude -F '%30p %d' search '~N'
> icingacli
>                            simple CLI tool for Icingaweb2 and its modules
>
> icingaweb2-common
>                            simple and responsive web interface for Icinga -
> common files
> libp8-platform-dev
>                           Pulse-Eight's platform support library --
> development files
> libp8-platform2
>                            Pulse-Eight's platform support library
>
> aptitude -F '%30p %d' search '~N' | head -3
> icingacli simple CLI tool for Icingaweb2 and its modules
> icingaweb2-common simple and responsive web interface for Icinga - common
> files
> libp8-platform-dev Pulse-Eight's platform support library -- development
> files
>
> Apart from the p column wider than 30 characters for the non-piped output,
> the piped version seems to ignore the width specification.
>
> Perhaps I'm still not understanding how to correctly use this?  Is there a
> way to have `aptitude search '~N' | head -3` produce aligned output?
>
> Right now the only solution I see is something ugly like the following
> # aptitude -F '%p %d' search '~N' | perl -ne 'printf("%-30s - %s\n",
> /(\S+) (.+)/)' | head -3
> icingacli                      - simple CLI tool for Icingaweb2 and its
> modules
> icingaweb2-common              - simple and responsive web interface for
> Icinga - common files
> libp8-platform-dev             - Pulse-Eight's platform support library --
> development files
>
>
> On Tue, Feb 23, 2016 at 12:19 PM, Manuel A. Fernandez Montecelo <
> manuel.montezelo at gmail.com> wrote:
>
>> Control: tags -1 + moreinfo unreproducible
>>
>>
>> Hi,
>>
>> 2016-02-23 18:34 nkiesel:
>>
>>> Package: aptitude
>>> Version: 0.7.6-1
>>> Severity: normal
>>>
>>> Dear Maintainer,
>>>
>>> version 0.7.6 changed the way output formatting is handled for the CLI
>>> version,
>>> and I consider that a regression.
>>>
>>> I use something like `aptitude search '~N' > t; less t`.  This used to
>>> truncate
>>> the output, but aptitude honored the `-w` switch, thus `aptitude search
>>> -w
>>> $COLUMNS > t; less t` worked in 0.7.4.
>>>
>>> 0.7.6 no longer allws that. Even specifying an output format using `-F`
>>> is
>>> silently ignored as soon as the output is redirected or piped.
>>>
>>
>> -F is honoured:
>>
>>    $ aptitude -w 60 -F '%p %v %V' search ~n^aptitude$
>>    aptitude                       0.7.6-1        0.7.6-1
>>    aptitude:i386                  <none>         0.7.6-1
>>
>>    $ aptitude -F '%p %v %V' search ~n^aptitude$ | cat
>>    aptitude 0.7.6-1 0.7.6-1
>>    aptitude:i386 <none> 0.7.6-1
>>
>>    $ aptitude -F '%p | %v | %V' search ~n^aptitude$ | cat
>>    aptitude | 0.7.6-1 | 0.7.6-1
>>    aptitude:i386 | <none> | 0.7.6-1
>>
>>
>> And in general, everything works in the same way, except that it doesn't
>> try to columnize the results and separates fields with single (instead
>> of multiple) spaces.
>>
>> And that's because, ultimately, when piping or redirecting aptitude
>> cannot know what will be the size on the other end, when viewing the
>> results.
>>
>>
>> I consider that a regression.  Actually, I never really understood why
>>> aptitude
>>> tried to recognize this situation in the first place.  If the idea is to
>>> allow
>>> an easier parsing, the caller should simply use a proper -F argument (of
>>> course; this also no longer works with 0.7.6).  Or perhaps add a
>>> `-m|--machine-
>>> friendly` parameter that forces this output format.
>>>
>>
>> I am not sure why you insist that it doesn't work and are so sure about
>> it, when it obviously does.
>>
>>
>> So please reconsider your decision wrt. redirection detection.
>>> Minimally, I
>>> would expect that `-F` is honored.  But ideally aptitude should just stop
>>> trying to be too smart here and simply produce the same output
>>> independent of
>>> if it goes to a terminal or something else.
>>>
>>
>> See #445206, #496728 for arguments on the contrary, which is the reason
>> why I worked on it in the first place.
>>
>>
>> Cheers.
>> --
>> Manuel A. Fernandez Montecelo <manuel.montezelo at gmail.com>
>>
>
>
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