You're reading from Linux Shell Scripting Bootcamp The fastest way to learn Linux shell scripting

Product type Paperback

Published in Jul 2017

Publisher Packt

ISBN-13 9781787281103

Length 208 pages

Edition 1st Edition

Tools

Linux

Concepts

Shell Scripting

Author (1):

James K Lewis

View More author details

Table of Contents (12) Chapters

Preface

1. Getting Started with Shell Scripting FREE CHAPTER

2. Working with Variables

3. Using Loops and the sleep Command

4. Creating and Calling Subroutines

5. Creating Interactive Scripts

6. Automating Tasks with Scripts

7. Working with Files

8. Working with wget and curl

9. Debugging Scripts

10. Scripting Best Practices

Index

Chapter 5 - Script 1

#!/bin/sh
#
# 5/16/2017
#
echo "script1 - Linux Scripting Book"

echo "Enter 'q' to quit."
rc=0
while [ $rc -eq 0 ]
do
 echo -n "Enter a string: "
 read str
 echo "str: $str"
 if [ "$str" = "q" ] ; then
  rc=1
 fi
done

echo "End of script1"
exit 0

And here is the output when run on my system:

This is a good one to run on your system. Try several different strings, numbers, and so on. Notice how the returned string contains whitespace, special characters, and so on. You don't have to quote anything, and if you do those will be returned as well.

You can also use the read command to put a simple pause into your script. This will allow you to see the output before it scrolls off the screen. It can also be used when debugging which will be shown in Chapter 9, Debugging Scripts.

The following script shows how to create a pause when the output gets to the last line of the screen:

Chapter 5 -...

The rest of the chapter is locked

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Authors (1)

James K Lewis

James Kent Lewis has been in the computer industry for over 35 years. He started out writing BASIC programs in high school and used punch cards in college for his Pascal, Fortran, COBOL, and assembly language classes. He himself learned the C programming language by writing various utilities, including a fully-functional text editor, which he uses everyday. He started out using DOS and AIX, and then OS/2. Linux is now his operating system of choice. Jim has worked in the past for several companies, including IBM, Texas Instruments, Tandem, Raytheon, Hewlett-Packard, and others. Most of these positions dealt with low-level device drivers and operating system internals. In his spare time he likes to create video games in Java.He has written articles for IBM Developer Works and has one patent.

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