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Bash Cookbook

You're reading from   Bash Cookbook Leverage Bash scripting to automate daily tasks and improve productivity

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Product type Paperback
Published in Jul 2018
Publisher Packt
ISBN-13 9781788629362
Length 264 pages
Edition 1st Edition
Languages
Tools
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Authors (2):
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Ganesh Sanjiv Naik Ganesh Sanjiv Naik
Author Profile Icon Ganesh Sanjiv Naik
Ganesh Sanjiv Naik
Ron Brash Ron Brash
Author Profile Icon Ron Brash
Ron Brash
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Toc

Table of Contents (10) Chapters Close

Preface 1. Crash Course in Bash FREE CHAPTER 2. Acting Like a Typewriter and File Explorer 3. Understanding and Gaining File System Mastery 4. Making a Script Behave Like a Daemon 5. Scripts for System Administration Tasks 6. Scripts for Power Users 7. Writing Bash to Win and Profit 8. Advanced Scripting Techniques 9. Other Books You May Enjoy

Avoiding command not found warnings/errors and improving portability


In this recipe, we are going to learn how to avoid warnings and errors in a shell script. For that, we are going to use the concept of redirection.

Getting ready

Besides having a terminal open, you need to have basic knowledge of the redirection technique.

How to do it...

Sometimes, while debugging your shell scripts, you may not want to view the errors or warning messages as well as your standard output. So for that, we are going to use the redirection technique. Now, we will write lynda as a command in our terminal. Run the command as follows.

$ lynda

You will get the command not found error. We can avoid this error by running the following command.

$ lynda 2> log.txt

We will write a script with a wrong syntax for declaring the variable. And we will redirect that error message to log.txt. Create a script avoid_error.sh, and write following content in it.

echo "Hello World"
a = 100
b=20
c=$((a+b))
echo $a

In the second line,...

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