Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Book Image

Linux Shell Scripting Cookbook, Second Edition - Second Edition

Overview of this book

The shell remains one of the most powerful tools on a computer system — yet a large number of users are unaware of how much one can accomplish with it. Using a combination of simple commands, we will see how to solve complex problems in day to day computer usage.Linux Shell Scripting Cookbook, Second Edition will take you through useful real-world recipes designed to make your daily life easy when working with the shell. The book shows the reader how to effectively use the shell to accomplish complex tasks with ease.The book discusses basics of using the shell, general commands and proceeds to show the reader how to use them to perform complex tasks with ease.Starting with the basics of the shell, we will learn simple commands with their usages allowing us to perform operations on files of different kind. The book then proceeds to explain text processing, web interaction and concludes with backups, monitoring and other sysadmin tasks.Linux Shell Scripting Cookbook, Second Edition serves as an excellent guide to solving day to day problems using the shell and few powerful commands together to create solutions.
Table of Contents (16 chapters)
Linux Shell Scripting Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Compressing data with gzip


gzip is a commonly used compression format in the GNU/Linux platform. It is one of the utilities (such as gzip, gunzip, and zcat) that handle gzip compression. However, gzip can be applied only on a single file or data stream. This means that it cannot archive directories and multiple files. Hence, we must first create a tar archive and compress it with gzip. Let's see how to operate with gzip.

How to do it...

gzip can be used both to compress files and decompress them back to the original:

  1. In order to compress a file with gzip use the following command:

    $ gzip filename
    $ ls
    filename.gz
    
  2. Extract a gzip compressed file as follows:

    $ gunzip filename.gz
    $ ls
    file
    
  3. In order to list out the properties of a compressed file use:

    $ gzip -l test.txt.gz
    compressed        uncompressed  ratio uncompressed_name
      35                   6 -33.3% test.txt
    
  4. The gzip command can read a file from stdin and also write a compressed file into stdout.

    Read data from stdin and output the compressed...