Mac OS X in a Nutshell

Chapter 25. Unix Command Reference

This chapter presents the Mac OS X user, programmer, and system administration commands available through the Terminal (see Chapter 19). Each entry is labeled with the command name on the outer edge of the page. The syntax line is followed by a brief description and a list of available options. Many commands come with examples at the end of the entry. If you need only a quick reminder or suggestion about a command, you can skip directly to the examples.

Typographic conventions for describing command syntax are in the Preface. For help in locating commands, see the index at the back of this book.

We’ve tried to be as thorough as possible in listing the options. The basic command information and most options should be correct; however, new options are added and sometimes old options are dropped. You may, therefore, find some differences between the options you find described here and the ones on your system. When there seems to be a discrepancy, check the manpage (by way of the man command). For most commands, you can also use the --help option to get a brief usage message. (Even when it isn’t a valid option, it usually results in an “invalid option” error message, along with the usage message.)

Traditionally, commands take single-letter options preceded by a single hyphen, like -d. A more recent Unix convention allows long options preceded by two hyphens, like --debug. Often, a feature can be invoked through either the old style or the new style ...