xcode-select

Install command line developer tools

$ xcode-select --install

$ xcode-select -p

$ sudo xcode-select -s [/Applications/Xcode.app]

$ sudo xcode-select -s [/Library/Developer/CommandLineTools]

$ sudo xcode-select -r

$ xcode-select --version

xcode-select [-h|-help] [-s path|--switch path] [-p|--print-path] [-r|--reset] [-v|--version] [--install]

xcode-select manages the active developer directory on macOS, controlling which Xcode or Command Line Tools installation is used by build tools like xcrun, xcodebuild, clang, and make.
The command line tools package includes compilers (clang, gcc), build tools (make, cmake), version control (git, svn), and the macOS SDK. When multiple Xcode versions are installed, xcode-select switches between them.
The tools are installed to /Library/Developer/CommandLineTools when using --install without full Xcode, or within /Applications/Xcode.app when using the full IDE.

--install

Install the command line developer tools (opens installer dialog)

Print path to the currently selected developer directory

Set the active developer directory to the specified path (requires sudo)

Reset to default developer directory search (requires sudo)

Print xcode-select version

Display help information

The --switch and --reset options require superuser privileges and affect all users on the system. After macOS updates, command line tools may need reinstallation. The --install command requires GUI interaction.

xcode-select has been part of macOS developer tools since Xcode 3. Apple separated Command Line Tools from Xcode proper around 2012, allowing development without the full IDE download.

xcrun(1), xcodebuild(1), clang(1), make(1)