Re: [Qemu-devel] [F.A.Q.] the advantages of a shared tool/kernel Git repository, tools/perf/ and tools/kvm/

[Arnaldo Carvalho de Melo]

Em Wed, Nov 09, 2011 at 11:40:01AM +0100, Gerd Hoffmann escreveu:
>   Hi,
> 
> > What we want to have is to have a set of distinctive colors - just 
> > two (background, foreground) colors are not enough - we also need 
> > colors to highlight certain information - we need 5-6 colors for the 
> > output to be maximally expressive. Is there a canonical way to handle 
> > that while still adapting to user preferences automatically by taking 
> > background/foreground color scheme of the xterm into account?
> 
> > I suspect to fix the worst of the fallout we could add some logic to 
> > detect low contrast combinations (too low color distance) and fall 
> > back to the foreground/background colors in that case.
> 
> As far I know it is pretty much impossible to figure the
> foreground/background colors of the terminal you are running on.  You

Glad to hear that, I thought I hadn't researched that much (I did). Hope
somebody appears and tell us how it is done :-)

> can try some guesswork based on $TERM (linux console usually has black
> background, xterm is white by default), but there will always be cases
> where it fails.
> 
> You can run without colors.  You can use bold to highlight things and
> reverse for the cursor.  Surely a bit limited and not as pretty as
> colored, but works for sure everywhere.
> 
> You can go for a linux-console style black background.  Pretty much any
> color is readable here, so you should have no problems at all to find
> the 5-6 colors you want.
> 
> You can go for a xterm-like light background, for example the lightgray
> used by older perf versions.  I like that background color, problem is
> with most colors the contrast is pretty low.  IMHO only red, blue and
> violet are readable on lightgray.  And black of course.
> 
> > Plus allowing full .perfconfig configurability of all the relevant 
> > colors, for those with special taste.
> 
> Sure.  Maybe also allow multiple color sections and pick them by $TERM
> or --colors switch, i.e. [colors "xterm"].

Its fully configurable as of now, what we need is a set of .perfconfigs
that show how people think its better, we try it, set it as the default,
leave the others in tools/perf/Documentation/perfconfig/color.examples.

- Arnaldo