The version of Unix that you’ll encounter in Mac OS X’s Terminal is similar to other versions you have seen, but dissimilar in some fundamental and often surprising ways. Although most tools are in their usual place, some are not on the system, while others are not where you would typically expect to find them on other Unix systems.
The lists shown in this section contain a sampling of the Unix commands developers will find on Mac OS X. It is, by no means, a complete list of the Unix utilities found on your system. Because there are so many commands, they are organized into several categories. If you are an experienced Unix user, many of these commands will be familiar to you, but we’ve referenced them here so you can quickly determine whether or not a command you need is available. Unless otherwise specified, all of the tools in the following lists can be found in /usr/bin or /usr/libexec. Some tools are available with the standard distribution of Mac OS X, but others are available only after installing the Developer Tools. (See Chapter 4 for more information about the Developer Tools). Appendix B contains a listing of commands that don’t have manpages on Mac OS X.