NO_COLOR Support

[rgchris]

(Related to #105)

Outside of using the interpreter in a REPL/Terminal environment (e.g. when using the interpreter for shell scripting), ANSI escape sequences obscures some system output. NO_COLOR support offers a solution for this.

More Info: https://no-color.org/

[Oldes]

Hi,

Could you be more specific, what output with colors is causing the problems? Because I never had problems with it so far. Actually I consider these codes as a bonus infornation (for example I used them for a colorized html output by converting these codes to html tags).

I can modify some parts like listing a directory, if it is wanted. But I'm not sure I have enough time to modify everything (like the help module where is a lot of hardcoded strings.. not using the helper ansi color funcions).

[rgchris]

Any output with ANSI sequences is a problem, e.g. HELP, logging, etc., even using the REPL in some cases. For me, the issue is requiring an intermediate process to strip these codes in a shell scripting environment (debugging, etc.). ANSI colors only really only apply when using the interpreter in the REPL/Terminal. Again, this would only apply when using the standard NO_COLOR environment variable.

[Oldes]

help is used in REPL, so it should not cause problems when using shell scripting. Maybe ?? should be modified as it may be useful even outside the REPL.

Logging is turned off, when used -q switch... like:

So I'm asking, if there is any other real example.

I'm not against supporting NO_COLOR env. variable. I just don't have time to modify everything myself and don't want to introduce checks for this value in every function call, which is supposed to provide colorized output (it would slow down execution).

Actually I can imagine, that having a --no-color argument would be more friendly.

Also... there is still user.reb script, which may be used to setup user's environment... one can easily replace the as-* functions which decorates with colors using something like:

if "true" = get-env 'NO_COLOR [
  as-gray:
  as-red:
  as-green:
  as-yellow:
  as-blue:
  as-purple:
  as-cyan:
  as-white: :quote
]

[rgchris]

Using logging and HELP to debug a shell script are real examples!

I appreciate that there are workarounds and that as a systemic request, it may not be a quick fix.

[Oldes]

Not all logs are converted... many codecs have hardcoded strings :/
Feel free to report if you find some issues.

[Oldes]

Btw... it is possible to modify log formatting... like:

It is not perfect, but better than all the hardcoded prints used in old codecs.

[acook]

There are also a variety of tools that can strip ANSI sequences from output. Those might be worth looking into. Or even making a similar tool in Rebol for general use.

[rebolek]

Color support console is clearly written for black background only. I'm using light scheme and some things are unreadable.

Instead of as-white and as-black, I would prefer as-bg, as-fg (or something similar) that can be easily changed with theming.

[Oldes]

These names are for terminal defaults, like these.

If some terminal is e.g. using blue instead of red, that does not mean that Rebol code should also switch these values.

Although you can redefine system/options/ansi values.
as-fg and as-bg are ugly names.

[Oldes]

Feel free to include as-black, as it is missing:)

[rebolek]

You don't understand the problem. If someone's using blue instead of red, that's of course their decision.

But if for example ?? hardcodes whole text as white, it makes it absolutely unusable for everyone who doesn't have black background. And that's not their problem, that's Rebol's problem because it's expecting everyone's using black background which is total nonsense.

That's why I proposed using foreground and background color instead of relying on black and white.

[Oldes]

So feel free to enhance the ansi... and hardcoded function usage.

[Oldes]

But still, if you have light theme, you would need to redefine your ansi/foreground value manually... there is no way how Rebol could know, what theme colors the terminal has.

[Oldes]

But I think, that in this case, there should be defined ansi/bright and that value used in the ?? function, instead of ansi/white