Book Image

Linux Utilities Cookbook

By : James Kent Lewis
Book Image

Linux Utilities Cookbook

By: James Kent Lewis

Overview of this book

<p>Linux is a stable, reliable and extremely powerful operating system. It has been around for many years, however, most people still don't know what it can do and the ways it is superior to other operating systems. Many people want to get started with Linux for greater control and security, but getting started can be time consuming and complicated. <br /><br />A practical, hands-on guide that provides you with a number of clear step-by-step examples to help you solve many of the questions that crop up when using an operating system you may not be familiar with.</p> <p>Presenting solutions to the most common Linux problems in a clear and concise way, this helpful guide starts with spicing up the terminal sessions by command retrieval and line editing, and shell prompt variables. We will then get to know the different desktops (GUIs) available for Linux systems and which is the best fit for you. We will then explore the world of managing files and directories, connectivity, and what to do when it goes wrong. We will also learn a range of skills, from creating and managing user accounts to securing your system, managing and limiting processes, and letting information flow from one process to another using pipes. Later, we will master disk management, working with scripts and automating tasks quickly, and finally, understand the need for a custom kernel and tips on how to build one.</p> <p><br />Based on the author's extensive experience, there is a section on best practices that every Linux user should be familiar with.</p>
Table of Contents (19 chapters)
Linux Utilities Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Using grep to find patterns


When dealing with files, it is convenient to be able to search for patterns within the text. This is often used in code development for example. Here we show how to use grep.

Getting ready

We will use the dmesg program, which shows information about the running kernel, for this example. If it is not available, or if your computer has been running for a long time, the following may not match up quite right on your system.

How to do it...

The following is an example on using grep:

  1. Run the following command:

    cd /tmp
    
  2. Use dmesg to create a file, so we can search for some information about your system:

    dmesg > dmesg1.txt
    
  3. Let's see if we can determine what network device is being used. Run:

    grep network dmesg1.txt
    
  4. The output might not be very informative. But what if case is an issue? Try the following command:

    grep -i network dmesg1.txt
    
  5. The -i tells grep to ignore case. You should now see which network driver your system is using. Now try the following command:

    grep ...