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
About the Authors
About the Reviewers

Parsing data from a website

It is often useful to parse data from web pages by eliminating unnecessary details. sed and awk are the main tools that we will use for this task. You might have come across a list of actress rankings in a grep recipe in the Chapter 4, Texting and driving; it was generated by parsing the website page

Let us see how we can parse the same data by using text-processing tools.

How to do it...

Let's go through the commands used to parse details of actresses from the website:

$ lynx -dump -nolist  | \
grep -o "Rank-.*" | \
sed -e 's/ *Rank-\([0-9]*\) *\(.*\)/\1\t\2/' | \
sort -nk 1 > actresslist.txt

The output will be as follows:

# Only 3 entries shown. All others omitted due to space limits
1   Keira Knightley 
2   Natalie Portman 
3   Monica Bellucci 

How it works...

Lynx is a command-line web browser—it can dump a text version of a website as we would see in a web...