Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Save more on your purchases now! discount-offer-chevron-icon
Savings automatically calculated. No voucher code required.
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
Mastering Linux Shell Scripting

You're reading from   Mastering Linux Shell Scripting A practical guide to Linux command-line, Bash scripting, and Shell programming

Arrow left icon
Product type Paperback
Published in Apr 2018
Publisher
ISBN-13 9781788990554
Length 284 pages
Edition 2nd Edition
Languages
Tools
Arrow right icon
Authors (2):
Arrow left icon
Mokhtar Ebrahim Mokhtar Ebrahim
Author Profile Icon Mokhtar Ebrahim
Mokhtar Ebrahim
Andrew Mallett Andrew Mallett
Author Profile Icon Andrew Mallett
Andrew Mallett
Arrow right icon
View More author details
Toc

Table of Contents (17) Chapters Close

Preface 1. The What and Why of Scripting with Bash FREE CHAPTER 2. Creating Interactive Scripts 3. Conditions Attached 4. Creating Code Snippets 5. Alternative Syntax 6. Iterating with Loops 7. Creating Building Blocks with Functions 8. Introducing the Stream Editor 9. Automating Apache Virtual Hosts 10. AWK Fundamentals 11. Regular Expressions 12. Summarizing Logs with AWK 13. A Better lastlog with AWK 14. Using Python as a Bash Scripting Alternative 15. Assessments 16. Other Books You May Enjoy

Counting arguments

As previously mentioned, the script name is the first argument at index 0 of the array. So, if we try to count the arguments, then the count should always be at the very least 1. In other words, if we have not supplied arguments, the argument count will be 1. To count the items in an array, we can use the len() function.

If we edit the script to include a new line we will see this work, as follows:

#!/usr/bin/python3
import sys
print("Hello " + sys.argv[1])
print( "length is: " + str(len(sys.argv)) )

Executing the code as we have earlier, we can see that we have supplied two arguments—the script name and then the string Mokhtar:

If we try and have a single print statement to print the output and the number of arguments, then it will produce an error because we can't concatenate integers with strings. The length value is an integer...

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 €18.99/month. Cancel anytime