Getting your macOS ready for C

Before any C can fly, the Mac needs a compiler. That sounds heavy. It is not.

I am not installing the full Xcode IDE here. For learning C we need a place to type, and a compiler in Terminal. Keep the rest out of the way.

Keep it simple

KISS — Keep It Simple, Stupid — is the whole plan for this page.

You need two tools:

1. An editor to write .c files — I use Sublime Text; any solid editor is fine.
2. Clang, Apple’s compiler, which arrives with the Command Line Tools package.

That is enough to compile Hello World on a Mac. Fancy IDEs can wait.

Install with Terminal

The cleanest path is already on your Mac. Open Terminal and run:

xcode-select --install

A system dialog appears. Choose Install, accept the license, and wait — the download is large. When it finishes, Clang and friends live under /Library/Developer/CommandLineTools.

You can read more about the switcher with man xcode-select.

Or download from Apple

If the dialog misbehaves, or you want a specific tools version, sign in at Apple Developer downloads, search for Command Line Tools, and install the package that matches your macOS.

Apple’s downloads list — pick the Command Line Tools package for your system

You do not need the full Xcode app for this course. Clang is one tool among the BSD-style command-line utilities in that package; installing the slim tools package is enough.

Next step

Compiler on the Mac. Next we add Harvard’s helper library so functions like get_string() work locally:

→ Installing the CS50 library