Re: add --color option to md5sum and shaXsum

[Pádraig Brady]

On 12/25/2013 01:00 PM, Florent Monnier wrote:
> 2013/12/24, Pádraig Brady wrote:
>> On 12/24/2013 12:25 PM, Florent Monnier wrote:
>>> Hello,
>>>
>>> This patch adds a --color option to the commands md5sum and shaXsum.
>>> The goal is to make it easier to visually identify similarities in a
>>> list of printed checksums.
>>>
>>> It takes action only if stdout is a tty.
>>>
>>> This patch can be applied on the version 8.22 of the coreutils.
>>>
>>
>> Sorry you've lost me. Why would you want this?
> 
> I use it since several months.
> It has helped me to read and compare more easily / more quickly checksums.
> 
> I would think that some other people using the *sum utils could try
> this --color feature a little, and after a while may say if they found
> it of some help or not.

I'm a proponent of using colors as they can help a lot:
http://www.pixelbeat.org/docs/terminal_colours/

I see others have used something similar:
http://rachelbythebay.com/w/2011/08/11/stripes/

>> If you wanted to compare hashes wouldn't it be better
>> to pipe to uniq with something like: md5sum * | uniq --group -w32
> 
> I just discovered from you this new feature --group from the uniq tool
> that appeared in the last 8.22 version.
> This is a very nice option and surely useful.
> 
> Now I still prefer to see colors in front of me.
> But I should try your solution, to compare, and I may change my mind
> after a while.
> 
> 
>> Also this doesn't strictly need to be within the *sum utils,
>> so if not of general use, it might be best done as a separate util
>> (which could also sort similarly perhaps)?
> 
> Sorry I don't understand what you mean.
> Do you mean that it should be an overlay tool, similar to colordiff?
> ( http://www.colordiff.org/ )

What I meant is that the output of the *sum utils has
enough info to be independently "colored" by something else.
If this was a very often used feature then it might make
sense to include within the *sum utils, though I'm not sure here...

> If this is what you mean, indeed I've also think at such a solution,
> but I just didn't do it because I found it easier to patch md5sum
> rather than writting a perl (or equivalent language) script.

... A separate tool could have more options like a larger color palette,
different formatting options than just directly coloring the checksum, ...

> The colordiff wrapper is written with Perl (5 if I'm not mistaken).
> I'm not that confident with Perl, this is not my main scripting
> language of choice. But it might be the appropriate language for
> writting a similar "colorchecksum" tool. I understand from your
> example that such a tool would provide more possibilities by combining
> it in multiple situations.
> 
> In your opinions, which programming/scripting language could be
> appropriate, beside perl, for writting such a tool?

Any general purpose language with good string handling,
for example python.

cheers,
Pádraig.