Proposal for new column(1) flag

Proposal for new column(1) flag

[Thomas Voss]

Hello there,

I'm not sure if this is exactly the right place to ask, so forgive me if
it isn't but I was thinking of a potential new flag for the column(1)
utility and would like to get some feedback on whether or not it would
even be accepted before I try to submit a patch.

The basic issue I am aiming to fix is this:  When you have a bunch of
lines and you want to display them in a more "human friendly" manner, you
may decide to display them using columns.  This is what ls does as the
default behavior when listing files and we can in theory do this by
piping the output of whatever command we run into column.  The issue I
found however is that the way column operates is by splitting each row
into multiple columns where every column has the same width (a width
which can hold the longest input line).  ls on the other hand tries to
make each column as thin as possible, with a gap of two spaces between
each column.  This means that in many cases ls can fit the same data into
more columns than center can.

Now when listing files this is not a problem, you can always use ls
instead of center.  But I recently found myself wanting to do this with a
list of movies that I had stored in a file, and so being able to just the
following would be much more convenient, but the gaps between the columns
is just too large:

	$ column movie-list

So my proposal is to add a new flag, perhaps -g (g for gap) which allows
you to specify how wide you want the gaps between the columns to be in
spaces, and then to columnate that way.  That change would make these two
lines identical:

	$ ls *
	$ ls * | column -g 2

- Thomas

Re: Proposal for new column(1) flag

[Bernhard Voelker]

[-- Attachment #1: Type: text/plain, Size: 1951 bytes --]

On 10/13/22 21:26, Thomas Voss wrote:
> Hello there,
> 
> I'm not sure if this is exactly the right place to ask, so forgive me if
> it isn't but I was thinking of a potential new flag for the column(1)
> utility and would like to get some feedback on whether or not it would
> even be accepted before I try to submit a patch.
> 
> The basic issue I am aiming to fix is this:  When you have a bunch of
> lines and you want to display them in a more "human friendly" manner, you
> may decide to display them using columns.  This is what ls does as the
> default behavior when listing files and we can in theory do this by
> piping the output of whatever command we run into column.  The issue I
> found however is that the way column operates is by splitting each row
> into multiple columns where every column has the same width (a width
> which can hold the longest input line).  ls on the other hand tries to
> make each column as thin as possible, with a gap of two spaces between
> each column.  This means that in many cases ls can fit the same data into
> more columns than center can.
> 
> Now when listing files this is not a problem, you can always use ls
> instead of center.  But I recently found myself wanting to do this with a
> list of movies that I had stored in a file, and so being able to just the
> following would be much more convenient, but the gaps between the columns
> is just too large:
> 
> 	$ column movie-list
> 
> So my proposal is to add a new flag, perhaps -g (g for gap) which allows
> you to specify how wide you want the gaps between the columns to be in
> spaces, and then to columnate that way.  That change would make these two
> lines identical:
> 
> 	$ ls *
> 	$ ls * | column -g 2
> 
> - Thomas

Hmm, you missed to give actual examples.  Is it like the output of this?

   $ ls * | column -xc $COLUMNS | column -t

(Example output in attached file to avoid line wrapping in the email.)

Have a nice day,
Berny

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ABCDEFHIJKLMNOPABCDEFHIJKLMNOPqwertyuiopasdfghjklzxcvbnm  ABCDEFHIJKLMNOPABCDEFHIJKLMNOPz1234     ABCDEFHIJKLMNOPABCDEFa1                          ABCDEFHIJKLMNOPABCDEFa2
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b1                                                        b2                                      qwertyuiopasdfghjklzxcvbnm                       z1234

Re: Proposal for new column(1) flag

[Bernhard Voelker]

oh, your 2 emails indeed didn't come thru ... I guess because there were 3 attachments.

Hereby forwarding...

On 10/17/22 12:27, Thomas Voss wrote:
> NOTE: Sorry if this email is a duplicate, I have been trying to send this
> for a good while but theres something wrong with my email client
> configuration that I need to try to figure out.
> 
> Also in my first email I made some references to "center", I actually
> meant to say "column", center is just a tool I was writing some code for
> when sending that email so it was stuck in my head.
> 
> ---
> 
> On Thu Oct 13, 2022 at 10:43 PM CEST, Bernhard Voelker wrote:
>> Hmm, you missed to give actual examples.  Is it like the output of
>> this?
>>
>>     $ ls * | column -xc $COLUMNS | column -t
> 
> Not quite, let me give you a real-world example (and the thing that
> prompted me to think of adding this feature).
> 
> I have a simple script on my system that has a list of movies, and I want
> to be able to display them all nicely in columns.  At the moment I am
> doing this, which is not optimal because the gaps between columns are too
> large, it results in 5 columns and 8 rows:
> 
>     $ column -x movie-list
> 
> This is what your suggestion looks like, and it also resuts in 5 columns
> and 8 rows but much more squished together:
> 
>     $ column -xc $COLUMNS movie-list | column -t
> 
> And finally this is a really stupid solution which creates a file for
> each line of the file and then uses ls to print them, it results in 6
> columns and 6 rows, which is more space-efficient, and what I would like
> to be able to get as output:
> 
>     #!/bin/sh
> 
>     while read f; do
>             touch $f
>     done <../movie-list
>     ls *
>     rm *
> 
> The outputs are included in files attached to this email

Have a nice day,
Berny

Re: Proposal for new column(1) flag

[Karel Zak]

On Thu, Oct 13, 2022 at 09:26:11PM +0200, Thomas Voss wrote:
> Hello there,
> 
> I'm not sure if this is exactly the right place to ask, so forgive me if
> it isn't but I was thinking of a potential new flag for the column(1)
> utility and would like to get some feedback on whether or not it would
> even be accepted before I try to submit a patch.
> 
> The basic issue I am aiming to fix is this:  When you have a bunch of
> lines and you want to display them in a more "human friendly" manner, you
> may decide to display them using columns.  This is what ls does as the
> default behavior when listing files and we can in theory do this by
> piping the output of whatever command we run into column.  The issue I
> found however is that the way column operates is by splitting each row
> into multiple columns where every column has the same width (a width
> which can hold the longest input line).  ls on the other hand tries to
> make each column as thin as possible, with a gap of two spaces between
> each column.  This means that in many cases ls can fit the same data into
> more columns than center can.
> 
> Now when listing files this is not a problem, you can always use ls
> instead of center.  But I recently found myself wanting to do this with a
> list of movies that I had stored in a file, and so being able to just the
> following would be much more convenient, but the gaps between the columns
> is just too large:
> 
> 	$ column movie-list
> 
> So my proposal is to add a new flag, perhaps -g (g for gap) which allows
> you to specify how wide you want the gaps between the columns to be in
> spaces, and then to columnate that way.  That change would make these two
> lines identical:
> 
> 	$ ls *
> 	$ ls * | column -g 2

I guess you want "table" mode for the column (see --table-* options).
It provides almost all features from libsmartcols. The next important
thing for your use-case is --output-separator, for example

  $ echo "AAA BBB CCC" | ./column -t --output-separator "..."
  AAA...BBB...CCC

of course you can use "   " to define space as separator, etc.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: Proposal for new column(1) flag

[Thomas Voss]

On Mon Oct 17, 2022 at 10:42 AM CEST, Karel Zak wrote:
> I guess you want "table" mode for the column (see --table-* options).
> It provides almost all features from libsmartcols. The next important
> thing for your use-case is --output-separator, for example
>
>   $ echo "AAA BBB CCC" | ./column -t --output-separator "..."
>   AAA...BBB...CCC
>
> of course you can use "   " to define space as separator, etc.

That doesn't quite work as a solution the moment that any item I want to
display in a column contains spaces though.

- Thomas