Chapter 5. The Linux Utilities

5. The Linux Utilities

IN THIS CHAPTER

Special Characters	126
Basic Utilities	127
less Is more: Display a Text File One Screen at a Time	128
Working with Files	129
lpr: Prints a File	131
| (Pipe): Communicates Between Processes	136
Compressing and Archiving Files	139
Obtaining User and System Information	146
Tutorial: Creating and Editing a File with vim	152

When Linus Torvalds introduced Linux and for a long time thereafter, Linux did not have a graphical user interface (GUI): It ran on character-based terminals only. All the tools ran from a command line. Today the Linux GUI is important but many peopleespecially system administratorsrun many command line programs. Command line utilities are often faster, more powerful, or more complete than their GUI counterparts. Sometimes there is no GUI counterpart to a textual utility; some people just prefer the hands-on feeling of the command line.

When you work with a command line interface, you are working with a shell (Chapters 7, 9, and 28). Before you start working with a shell, it is important that you 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 five basic utilities: ls, cat, rm, 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 archive files.

Tip: Run these utilities from a command line

This chapter describes command line, or textual, utilities. You can experiment with these utilities from a terminal, a terminal emulator within a GUI (page 93), or a virtual console (page 113).