zsh-syntax-highlighting

Fish-style live highlighting of the command line as you type. Its real job is catching errors before Enter: a command name in red means zsh can't find it. Cloned as a chezmoi external into ~/.oh-my-zsh/custom/plugins/.

You see	It means
green command	resolves — binary, alias, function, or builtin
red command	typo / not installed — this will fail
underlined word	exists as a valid file path
yellow quotes	string literal (unclosed quotes stay obviously open)

Pro tips

• Treat red as a pre-flight check. chezmoi, kubectl, terrafrom — if it's still red when you finish the word, you've typo'd it or the brew install hasn't happened. Zero-cost dry run on every command.
• The underline is a path validator: type a filename argument and if it gains an underline, the file exists — no more ls just to double-check a path before rm or mv.
• Green also confirms an alias or function resolves — useful sanity check after editing aliases.zsh or re-running chezmoi apply.
• It highlights matched vs. unmatched quotes and brackets as you type — when a long one-liner looks wrong at the far end, the colors show where the quoting went sideways.
• Load order is law: it must be the last plugin in plugins=(...) in dot_zshrc, with one blessed exception — history-substring-search, whose README requires loading after syntax-highlighting. That's exactly the ordering committed there; don't "alphabetize" it.