3.5. Superuser Privileges with sudo

Most Mac OS X user accounts run with restricted privileges; there are parts of the filesystem to which you don't have access, and there are certain activities that are prohibited until you supply a password. For example, when you run the Software Update utility from System Preferences, Mac OS X may ask you for your password before it proceeds. This extra authentication step allows Software Update to run installers with superuser privileges.

You can invoke these same privileges at the command line by prefixing a command with sudo (short for "superuser do"), a utility that prompts you for your password and executes the command as the superuser. You must be an administrative (or admin, for short) user to use sudo. The user you created when you first set up your Mac is an admin user . You can add new admin users or grant admin status to a user in System Preferences → Accounts, as shown in Figure 3-11.