Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Learning Linux Shell Scripting

You're reading from   Learning Linux Shell Scripting Unleash the power of shell scripts to solve real-world problems by breaking through the practice of writing tedious code

Arrow left icon
Product type Paperback
Published in Dec 2015
Publisher
ISBN-13 9781785286216
Length 306 pages
Edition 1st Edition
Arrow right icon
Author (1):
Arrow left icon
Ganesh Sanjiv Naik Ganesh Sanjiv Naik
Author Profile Icon Ganesh Sanjiv Naik
Ganesh Sanjiv Naik
Arrow right icon
View More author details
Toc

Table of Contents (14) Chapters Close

Preface 1. Getting Started and Working with Shell Scripting FREE CHAPTER 2. Drilling Deep into Process Management, Job Control, and Automation 3. Using Text Processing and Filters in Your Scripts 4. Working with Commands 5. Exploring Expressions and Variables 6. Neat Tricks with Shell Scripting 7. Performing Arithmetic Operations in Shell Scripts 8. Automating Decision Making in Scripts 9. Working with Functions 10. Using Advanced Functionality in Scripts 11. System Startup and Customizing a Linux System 12. Pattern Matching and Regular Expressions with sed and awk Index

Exiting from a loop with a break


In the previous section, we discussed about how continue can be used to exit from the current iteration of a loop. The break command is another way to introduce a new condition within a loop. Unlike continue, however, it causes the loop to be terminated altogether if the condition is met.

In the for_12.sh script, we check the directory's content. If the directory is found, then we are exiting the loop and displaying the message that the first directory is found:

#!/bin/bash
rm -rf sample*
echo > sample_1
echo > sample_2
mkdir sample_3
echo > sample_4

for file in sample*
do
  if [ -d "$file" ]; then
    break;
  fi
done

echo The first directory is $file
rm -rf sample*
exit 0

Let's test the program:

$ chmod +x for_12.sh
$ ./for_12.sh

The following will be the output after executing the preceding commands:

The first directory is sample_3

In the for_13.sh script, we ask the user to enter any number. We print the square of numbers in the while loop. If...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime