Book Image

Linux Shell Scripting Bootcamp

By : James K Lewis
Book Image

Linux Shell Scripting Bootcamp

By: James K Lewis

Overview of this book

Linux Shell Scripting Bootcamp is all about learning the essentials of script creation, validating parameters, and checking for the existence of files and other items needed by the script. We will use scripts to explore iterative operations using loops and learn different types of loop statements, with their differences. Along with this, we will also create a numbered backup script for backup files. Further, you will get well-versed with how variables work on a Linux system and how they relate to scripts. You’ll also learn how to create and call subroutines in a script and create interactive scripts. The most important archive commands, zip and tar, are also discussed for performing backups. Later, you will dive deeper by understanding the use of wget and curl scripts and the use of checksum and file encryption in further chapters. Finally, you will learn how to debug scripts and scripting best practices that will enable you to write a great code every time! By the end of the book, you will be able to write shell scripts that can dig data from the web and process it efficiently.
Table of Contents (19 chapters)
Linux Shell Scripting Bootcamp
About the Author
About the Reviewer
Customer Feedback

wget options

Normally the defaults used by wget are good enough for most users, however, you may need to tweak things from time to time to get it to work the way you want it to.

Here is a partial list of some of the wget options:

wget option


-o filename

Output messages to a log file. This was covered earlier in the chapter.

-t number

Try number times before giving up on the connection.


Continue to download a partially downloaded file from a previous wget.


Display the headers sent by the server.

-Q number

The quota, or total amount of bytes that will be downloaded. Number can be in bytes, kilobytes (k), or megabytes (m). Set to 0 or inf for no quota.

-l number

This specifies the maximum recursion level. The default is 5.


This is good for when trying to create a mirror of a site. It is equivalent to using the -r -N -l inf --no-remove-listing options.

Another thing you may try is to turn on debugging with the -d option. Note that this will only work...