(Ab?)using aliases to set ls' and others' colours

[Tobias Geerinckx-Rice]

Tobias Geerinckx-Rice wrote:
> Björn Höfling wrote:
> > ls has a colored output. Nice.
> > ls | less has ugly escape sequences. Only ls --color=no | less
> > works.
>
> I'd be surprised if ‘ls | less -R’ didn't (and that would be a 
> bug).
>
> Otherwise, this is standard behaviour for both ‘ls’ and ‘less’.

Apologies, I made a reado.

‘ls | $foo’ should indeed detect a missing tty and stop spewing 
colour automatically. At least if ‘ls’ is properly aliased to ‘ls 
--color=auto’.

Instead, it is aliased[0] to use ‘--color’ — short for ‘ls 
--color=always’ — for reasons I cannot understand. We do the same 
for ‘grep’.

Perhaps it was assumed that ‘--color’ on its own implies ‘auto’ 
instead of ‘always’ (I could see how that could happen)? Or 
‘--color=auto’ is too cautious, and disables colour in a situation 
where the author expects it? In that case I don't think the 
trade-off is worth it.

On the other hand, what I consider an obvious bug has been around 
since literal forever[1], so maybe I'm missing something obvious 
here. I've CC'd the original author. If everyone agrees or nobody 
responds, I'd like to change it to something less aggressive 
before 0.15.[2]

What? Not sure yet. I'm not even sure this should be handled by 
aliases at all. Our default ‘ls’ alias also adds a ‘-p’, which is 
probably valid [although I find it useless and annoying and 
disable it], but colours for both commands can also be controlled 
through the {LS,GREP}_COLORS variables which seems like a better 
fit for distro defaults like these. We can even change the 
colours! But let's not.

Oh, I don't know.

This is the kind of trivial bug that would've put me off a distro, 
I guess.

Kind regards,

T G-R

[0]: in gnu/system/shadow.scm
[1]: 2013, at least: 0b86a82dc7e649e4ae551edefba445690a315b83
[2]: I'm already doing so in my own .bashrc, which has drifted 
away from Guix's current upstream version, which is its own little 
annoying gotcha.