Syntax highlighting in the console using ZSH

zsh-syntax-highlighting is another gem for ZSH — assuming you've already installed Oh-My-Zsh (see How to install Oh-My-ZSH if not).

As you type, you'll be able to tell from the colors that, for example, something isn't quite right.

If you type head followed by a space, ZSH will display this word in green: this command exists and is valid. If you type heat there, the word will appear in red: this command does not exist.

It sounds simple, but it's so practical.

What Syntax Highlighting Looks Like​

Type a command like cat or head and it turns green: the command exists, it's correctly typed and it's executable.

Make a typo and the very same word turns red before you even press ENTER:

That color appears while you type, not after the command has failed. You know you've mistyped docekr before losing a second to a command not found.

How to use it​

In fact, nothing has to be done: there is no configuration file, no option to set, no alias to define. Install the plugin, reload your shell, and the coloring is simply there from the next character you type.

Seeing It in Action with Docker​

No history to seed, no config to write — this plugin needs nothing but itself, which makes it a perfect one-command Docker test.

Build and run it:

$ docker build -t syntax-demo .
[+] Building 18.4s (7/7) FINISHED
✔ exporting to image
$ docker run --rm -it syntax-demo
🐳 root ~ # head

Type head and the word turns green as you finish typing it — the command exists. Backspace it, type heat or docekr instead, and it turns red before you even press ENTER: same scene as the two screenshots above, live in your own terminal.

Installation​

Just clone the official repository like below:

$ git clone https://github.com/zsh-users/zsh-syntax-highlighting ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting▋

Then edit the ~/.zshrc file, search for plugins=( and add zsh-syntax-highlighting to the list. You'll have f.i. something like:

plugins=(?
  git
  # ... your existing plugins
  zsh-syntax-highlighting?
)

Close your console, open a new one (or run source ~/.zshrc to load your change) and it's done.

Conclusion​

Two lines of setup and your terminal starts proofreading you: green means "this will run", red means "fix me first". It's the kind of tiny feedback loop you stop noticing after a week — until you sit at a machine without it and start typing blind again.

Its natural companion is Autosuggestions in the console using ZSH: this one tells you whether what you're typing is valid, the other saves you from typing it at all.