Why does my IRB prompt with ANSI color codes mess up page up/down behavior with copy/paste?

Question

I added to my .irbrc:

IRB.conf[:PROMPT].reverse_merge!(:RAILS_ENV => {:PROMPT_I=>"#{current_app} #{rails_env} #{prompt} ", :PROMPT_N=>"#{current_app} #{rails_env} #{prompt} ", :PROMPT_S=>nil, :PROMPT_C=>"?> ", :RETURN=>"=> %s\n"}) 
IRB.conf[:PROMPT_MODE] = :RAILS_ENV

If I do something like:

current_app = "\e[31mfoo_bar_app\e[0m"
rails_env = "\e[32m#{RAILS_ENV}\e[0m"

then the prompt shows up beautifully colorized, but if I copy some text into my copybuffer and paste it, if I do page-up/page-down to go to the beginning/end of the current text entered, my cursor like jumps to the middle of the text for page-up, and for page-down it jumps way out to the right into an area of blank spaces where nothing had been typed, then my cursor position is totally screwed up.

Is there a way I can correct this? I would really like a colorized prompt.

Heptode

which terminal-setup are you using? e.g. terminal emulator and shell? – Veolaver

Answer 1

I'd be willing to bet this is similar to the question I asked in Colorized output breaks linewrapping with readline

Try this:

current_app = "\001\e[31mfoo_bar_app\e[0m\002"
rails_env = "\001\e[32m#{RAILS_ENV}\e[0m\002"

Basically, your prompt is not ignoring non-printing characters which causes weird things to happen.

Gatt

Only the control codes which set the color should be surrounded by \001 and \002, not the text which is to be printed in color. Otherwise you have a problem in the other direction. – Behest

Answer 2

Yes, only color code need to be in \001 and \002 like this

\001\e[37m\002[%~] #{RUBY_VERSION}-p#{RUBY_PATCHLEVEL} - r#{release}\001\e[0m\002production

Medication