rainbow-parens

The CLI, not the editor extension.

rainbow-parens is a small console utility for adding rainbow parentheses to unix streaming stdin.

If you're not familiar with rainbow parentheses, they're an editor feature where each pair of parentheses, braces, and brackets is rendered a distinct color, so you can find the open and close more easily when looking at the screen. It's great! Sometimes you want to be able to add rainbow parentheses to other things though, for instance, if you're writing tests and need to dump a large complex JSON object, or you're staring at logs from a system with a complex log format. This little CLI lets you add rainbow brackets to any file or streaming input.

Installation

A Linux-compatible binary and NodeJS script will be published for each release. The NodeJS script should work for everyone and is smaller than the published binary by a considerable amount but also requires NodeJS.

Linux Binary

If you're on a Linux system, you can download the binary and put it somewhere on your path and you'll be all set, e.g.:

# copy the actual URL from the latest release
$ wget https://github.com/jisantuc/rb-paren-cli/... 
$ cp rainbow-parens /usr/local/bin/

NodeJS script

If you're not on a Linux system or your Linux system is incompatible with the compiled binary, you can use the NodeJS script. To do so, download the script somewhere sensible then create an alias that invokes it with NodeJS. For example:

# copy the actual URL from the latest release
$ wget \
    -o $HOME/.local/bin/rainbow-parens.js \
    https://github.com/jisantuc/rb-paren-cli/...
# or .bash_profile, or .bashrc, or wherever it is you configure aliases
# for your shell sessions
$ echo 'alias rainbow-parens="node $HOME/.local/bin/rainbow-parens.js"' >> ~/.zshrc

Then you can use rainbow-parens normally.

Color configuration

The default rainbow uses ANSI red for un-matched closing characters and ANSI colors for the rainbow. But if you want, you can have so many more colors!

The CLI accepts a palette argument that will let you specify the color rotation in two different ways -- you can use comma-separated hex colors (with or without leading # symbols) or comma-separated rgb(byte,byte,byte) values. The last value in the list will be treated as the error color, so you must specify at least two values if you want to configure a palette.

You can see example palette configurations in the CLI help:

$ rainbow-parens --help
Usage: rb-paren-cli [--palette <color,color,color,errorColor>] [<file>]

...
    --palette <color,color,color,errorColor>
         Comma-separated list of rgb(x,y,z) or hex colors (in 8 bit color space).
         The last color in the list will be interpreted as the error color.
         Example: rgb(0,255,255),rgb(255,0,255),rgb(255,255,0)
                  000000,0000ff,00ff00,ff0000

The two examples aren't very pretty, but they get the point across. If you want to generate some palettes, you can check out coolors and mess with tints to get more colors. For instance, using colors from this random generation: