[chriswarbo]

You may not have issue with the sort of things you use it for, but others might.

For example, I run shells in Emacs and have had to tweak loads of shell scripts written by colleagues to fix their poorly-implemented colourisation. It's useful to know when a test has failed; it's not so useful to have the whole terminal set to white text on a pale pink background.

One day I couldn't SSH into our servers from Emacs. It turned out somebody had edited .bashrc for the admin user to make the bash prompt blue. Emacs' TRAMP process was looking for a prompt ending in "$" or "#", not "$\[\033[0m\]", so it didn't realise the connections were successful.

There are two ways of handling this: we can blame the source of the bug (the person adding the colours incorrectly, or the assumption-loaded TRAMP regex), but there will always be more bugs in situations we'd never think of. Alternatively, we can avoid being 'too clever', and instead aim for consistency and least surprise.

[gknoy]

As much as I love Emacs, that sounds like it's a bug to assume that one's prompt will follow a convention (ends-in-$). The convention is useful and good, but it seems strange to blame someone for breaking your tool's expectations when they had made a valid prompt.

[philh]

Are you suggesting that colored prompts violate the rules of consistency and least surprise?

(Actually, if you are suggesting that, I'm not going to disagree. But I am going to say that if so, those rules don't apply in the case of colored prompts, because colored prompts are useful.)

[chriswarbo]

I suppose I'm suggesting that, aside from personal scripts, we shouldn't assume too much about who our users are and what they're trying to do. The principle of least power tells us to use the dumbest format that will work, eg. plain text.

Anything we add on top of that, eg. ANSI colour codes, will be useful to some but harmful to others. The tricky part is working out which of those categories the current user is in.

[philh]

So is your proposed solution not to have colored prompts? (I vehemently disagree.) Or not to put them in a .bashrc? (I still disagree, but only strongly.) Or something else?

[prakashk]

The main problem here is that a change that should have been done as part of an individual's customization was made to a shared configuration file.

[wtbob]

Or, y'know, have coloured prompts but place the escape characters such that they don't mess with prompt-detection regexps.

[philh]

To be precise, what you're suggesting is that we have prompts which are allowed to be colored except for the $/# at the end, because you can't color those without following them by escape characters. And that prompts must have a $/# at the end.

I don't consider that an acceptable solution.