Book Image

Bash Cookbook

By : Ron Brash, Ganesh Sanjiv Naik
Book Image

Bash Cookbook

By: Ron Brash, Ganesh Sanjiv Naik

Overview of this book

In Linux, one of the most commonly used and most powerful tools is the Bash shell. With its collection of engaging recipes, Bash Cookbook takes you through a series of exercises designed to teach you how to effectively use the Bash shell in order to create and execute your own scripts. The book starts by introducing you to the basics of using the Bash shell, also teaching you the fundamentals of generating any input from a command. With the help of a number of exercises, you will get to grips with the automation of daily tasks for sysadmins and power users. Once you have a hands-on understanding of the subject, you will move on to exploring more advanced projects that can solve real-world problems comprehensively on a Linux system. In addition to this, you will discover projects such as creating an application with a menu, beginning scripts on startup, parsing and displaying human-readable information, and executing remote commands with authentication using self-generated Secure Shell (SSH) keys. By the end of this book, you will have gained significant experience of solving real-world problems, from automating routine tasks to managing your systems and creating your own scripts.
Table of Contents (15 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Finding binary dependencies


In this section, we are going to check the executable. We will find out which string is present in it by using the string command.

Getting ready

Besides having a terminal open, make sure you have a binary present in your directory.

How to do it...

  1. First, we will check the executable. Run the following command:
$ file binary_name
  1. Now we will write a command to find strings within the binary. Run the following command:
$ strings binary_name
  1. We can hexdump a file by running the following command:
$ od -tx1 binary_name
  1. We can list the symbols in the binary by running the following command:
$ nm binary_name
  1. You can check which shared library it has been linked with by running the following command:
$ ldd binary_name

How it works...

Now we will look at an explanation of the previous commands:

  1. We used the file command to get the information about the binary. We also got the architecture information by running the file command.
  2. The string command will return the string within that binary...