UNIX® Shells by Example, Third Edition

Chapter 2. The UNIX Toolbox

There are hundreds of UNIX utilities available, and many of them are everyday commands such as ls, pwd, who, and vi. Just as there are essential tools that a carpenter uses, there are also essential tools the shell programmer needs to write meaningful and efficient scripts. The three major utilities that will be discussed in detail here are grep, sed, and awk. These programs are the most important UNIX tools available for manipulating text, output from a pipe, or standard input. In fact, sed and awk are often used as scripting languages by themselves. Before you fully appreciate the power of grep, sed, and awk, you ...