Chapter 3. The Mac OS X Utilities

3. The Mac OS X Utilities

IN THIS CHAPTER

Special Characters	40
Basic Utilities	41
less: Displays a Text File One Screen at a Time	42
Working with Files	43
lpr: Prints a File	45
| (Pipe): Communicates Between Processes	51
Compressing and Archiving Files	54
Locating Commands	58
apropos: Searches for a Keyword	59
Obtaining User and System Information	60

When the first UNIX systems were introduced, and for a long time thereafter, UNIX did not have a graphical interface: It ran on character-based terminals only. All the tools ran from the command line. The Mac OS X GUI is important, of course, but many peopleespecially system administratorsrun many command line programs. In a lot of cases, command line utilities are faster, more powerful, or more complete than their GUI counterparts. Sometimes there is no GUI counterpart for a text-based utility, and some people just prefer the hands-on feeling of the command line.

When you work with a command line interface, you are working with the shell (Chapters 5, 8, and 13). Before you start working with the shell, it is important to understand something about the characters that are special to the shell, so this chapter starts with a discussion of special characters. The chapter then describes six basic utilities: ls, cat, rm, open, less, and hostname. It continues by describing several other file manipulation utilities as well as utilities that find out who is logged in; that communicate with other users; that print, compress, and decompress files; and that pack and unpack archived files.

Tip: Run these utilities from a command line

This chapter describes command line, or text-based, utilities. You can experiment with these utilities from the Terminal utility (page 24), a terminal emulator within a GUI.