hopkinsr / terminal-color

A Racket library to output colored text to the terminal on any platform, including Windows

terminal-color

A Racket library to output colored text to the terminal on any platform, including Windows.

NOTE: This library is currently in development so things may change before v1.0 is released. The current version should be usable on all platforms with Racket 5.3.6 and 6.x series. Compatability will try to be kept for existing users.

Documentation

A rendered version of the documentation for this library is available via Github Pages:

• https://hopkinsr.github.io/terminal-color/

Example

In short this library provides corresponding procedures for the standard display, displayln, print and write procedures, allowing you to write things like

(require terminal-color)

(displayln-color "1: Default colors")
(displayln-color "2: Green" #:fg 'green)
(displayln-color "3: White on red" #:fg 'white #:bg 'red)

Requirements

It should be possible to install this package as normal using raco on both Racket 5.3.6 and 6.x.

terminal-color's Issues

Register the package with https://pkgs.racket-lang.org/

I tried to search terminal-color in pkgs.racket-lang.org and couldn't find it.

Issues in combination with charterm

Obviously not a bug per se. More a plea for help from someone who understands terminal internals.

I'm on Ubuntu 14.04 (gnome-terminal; TERM=xterm). I'm trying to use http://www.neilvandyke.org/racket-charterm to move the cursor around, etc. and terminal-color to print in color after moving around. It seems to work just enough to keep me interested. For example (after requireing charterm and terminal-color):

(open-charterm)
(charterm-clear-screen)
(charterm-cursor 5 5)
(displayln-color "Hello" #:fg 'green)  ; works
(close-charterm)

This works great. The screen shows "Hello" at 5,5 on the screen. However, replacing the displayln-color with display-color causes the text to appear at row 5, col 1. Using charterm-newline or charterm-clear-line sometimes gives me the sense that display doesn't immediately update the screen. Do you have any idea what might be going on? Is combining these two libraries just a bad idea because of incompatible internals or something? Thanks.

True Color Syntax

I like this library. One thing I would add as a feature request is a syntax for 24-bit "true color" support. In recent years they've made a standard for specifying 24-bit color for terminals and most terminal emulators support it. Here is an old gist that explains what ones support it so far:

https://gist.github.com/XVilka/8346728

You could have the interface be something like this (maybe accepting the strings with or without the leading # sign):

(displayln-color "Purple on orange" #:fg "#9C0874" #:bg "#F09C26")

The sequences to get 24-bit color are:

\e[38;2;R;G;Bm

Where R, G, and B range from 0 to 255. Replace 38 with 48 for background.

This is pretty well supported currently for Unix terminal emulators (including OSX), and I expect it to gradually take off as the norm for most console applications that want to deal with more than 8 colors. Windows may never support such a thing, but I think it's worth having for those who program for Unix.