GNU bug report logs - #20120
wc output padding differs when "-" is in the file list

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Eric Mrak <mail <at> ericmrak.info>
To: bug-coreutils <at> gnu.org
Subject: wc output padding differs when "-" is in the file list
Date: Sun, 15 Mar 2015 22:42:59 -0700

[Message part 1 (text/plain, inline)]

It seems that whenever STDIN is involved the results padding reverts to the
BSD-style 7/8 padding. When files are given as input (excluding STDIN) the
padding reflects the width of the largest count. When files are given as
input and one of these is "-", the padding reverts again to the BSD 7/8
padding.

System: Arch Linux (package: core/coreutils 8.23-1)

===================
$ wc --version
wc (GNU coreutils) 8.23
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html
>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Paul Rubin and David MacKenzie.
===================

Actual:

===================
$ echo "some text" > test.txt
$ printf %s "one\ntwo\nthree" | wc - test.txt
      3       3      14 -
      1       2      10 test.txt
      4       5      24 total
===================

Expected:

===============
$ echo "some text" > test.txt
$ printf %s "one\ntwo\nthree" | wc - test.txt
 3  3 14 -
 1  2 10 test.txt
 4  5 24 total
===================

[Message part 2 (text/html, inline)]

Message #8 received at 20120 <at> debbugs.gnu.org (full text, mbox):

From: Bernhard Voelker <mail <at> bernhard-voelker.de>
To: Eric Mrak <mail <at> ericmrak.info>, 20120 <at> debbugs.gnu.org
Subject: Re: bug#20120: wc output padding differs when "-" is in the file list
Date: Wed, 18 Mar 2015 18:54:05 +0100

On 03/16/2015 06:42 AM, Eric Mrak wrote:
> It seems that whenever STDIN is involved the results padding
> reverts to the BSD-style 7/8 padding. When files are given
> as input (excluding STDIN) the padding reflects the width of
> the largest count.
> When files are given as input and one of these is "-", the
> padding reverts again to the BSD 7/8 padding.

Thanks for the report.
This effect is there at least since the last bigger change in
this area, the introduction of the function compute_number_width(),
back in 2003.

Furthermore, strange formatting also happend in other cases,
e.g. for other non-regular files ...

  $ wc /etc/hosts /dev/null
       41     124    1355 /etc/hosts
        0       0       0 /dev/null
       41     124    1355 total

... or where stat() returns a wrong value like for /proc files ...

  $ wc /proc/cpuinfo x
  52 256 1276 /proc/cpuinfo
  1 0 1 x
  53 256 1277 total

... or with the --files0-from=FILE option:

  $ printf '%s\0' x /etc/hosts | wc --files0=-
  1 0 1 x
  41 124 1355 /etc/hosts
  42 124 1356 total

The number width is determined before reading the actual files.
I'm asking myself if it would hurt to save the values for all files
until all of them are read, and then do the calculation of the
number width and the printing of all values.
OTOH this would delay output until all files are read (besides
the memory footprint).
Any opinions if a proper output format warrants this disadvantages?

Regarding the number width fallback of %7d: this is mentioned in
the POSIX specification (in 'Rationale'), but I'm unsure if it's
mandated/ recommended/deprecated behavior.
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/wc.html

Have a nice day,
Berny

Message #11 received at 20120 <at> debbugs.gnu.org (full text, mbox):

From: Pádraig Brady <P <at> draigBrady.com>
To: Bernhard Voelker <mail <at> bernhard-voelker.de>, 
 Eric Mrak <mail <at> ericmrak.info>, 20120 <at> debbugs.gnu.org
Subject: Re: bug#20120: wc output padding differs when "-" is in the file list
Date: Thu, 19 Mar 2015 10:38:11 +0000

On 18/03/15 17:54, Bernhard Voelker wrote:
> On 03/16/2015 06:42 AM, Eric Mrak wrote:
>> It seems that whenever STDIN is involved the results padding
>> reverts to the BSD-style 7/8 padding. When files are given
>> as input (excluding STDIN) the padding reflects the width of
>> the largest count.
>> When files are given as input and one of these is "-", the
>> padding reverts again to the BSD 7/8 padding.
> 
> Thanks for the report.
> This effect is there at least since the last bigger change in
> this area, the introduction of the function compute_number_width(),
> back in 2003.
> 
> Furthermore, strange formatting also happend in other cases,
> e.g. for other non-regular files ...
> 
>    $ wc /etc/hosts /dev/null
>         41     124    1355 /etc/hosts
>          0       0       0 /dev/null
>         41     124    1355 total
> 
> ... or where stat() returns a wrong value like for /proc files ...
> 
>    $ wc /proc/cpuinfo x
>    52 256 1276 /proc/cpuinfo
>    1 0 1 x
>    53 256 1277 total
> 
> ... or with the --files0-from=FILE option:
> 
>    $ printf '%s\0' x /etc/hosts | wc --files0=-
>    1 0 1 x
>    41 124 1355 /etc/hosts
>    42 124 1356 total
> 
> The number width is determined before reading the actual files.
> I'm asking myself if it would hurt to save the values for all files
> until all of them are read, and then do the calculation of the
> number width and the printing of all values.
> OTOH this would delay output until all files are read (besides
> the memory footprint).
> Any opinions if a proper output format warrants this disadvantages?

Changing to unbounded memory (albeit slowly increasing) is not worth it I think.

> Regarding the number width fallback of %7d: this is mentioned in
> the POSIX specification (in 'Rationale'), but I'm unsure if it's
> mandated/ recommended/deprecated behavior.
> http://pubs.opengroup.org/onlinepubs/9699919799/utilities/wc.html

The existing padding is only a nicety.
If I was going to change anything, I'd add field selection and left/right
alignment support to column(1).

cheers,
Pádraig.

Message #14 received at 20120 <at> debbugs.gnu.org (full text, mbox):

From: Assaf Gordon <assafgordon <at> gmail.com>
To: 20120 <at> debbugs.gnu.org
Subject: Re: bug#20120: wc output padding differs when "-" is in the file list
Date: Mon, 22 Oct 2018 20:01:07 -0600

tags 20120 wontfix
close 20120
stop

(triaging old bugs)

On 19/03/15 04:38 AM, Pádraig Brady wrote:
> On 18/03/15 17:54, Bernhard Voelker wrote:
>> On 03/16/2015 06:42 AM, Eric Mrak wrote:
>>> It seems that whenever STDIN is involved the results padding
>>> reverts to the BSD-style 7/8 padding. 
>>
>> Thanks for the report.
>> This effect is there at least since the last bigger change in
>> this area, the introduction of the function compute_number_width(),
>> back in 2003.
>
> The existing padding is only a nicety.
> If I was going to change anything, I'd add field selection and left/right
> alignment support to column(1).

Given the above, and without further comments in 3 years,
I'm closing this bug.

Discussion can continue by replying to this thread.

-assaf

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