Search icon CANCEL
Subscription
0
Cart icon
Cart
Close icon
You have no products in your basket yet
Save more on your purchases!
Savings automatically calculated. No voucher code required
Arrow left icon
All Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletters
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Bash Cookbook

You're reading from  Bash Cookbook

Product type Book
Published in Jul 2018
Publisher Packt
ISBN-13 9781788629362
Pages 264 pages
Edition 1st Edition
Languages
Authors (2):
Ron Brash Ron Brash
Profile icon Ron Brash
Ganesh Sanjiv Naik Ganesh Sanjiv Naik
Profile icon Ganesh Sanjiv Naik
View More author details
Toc

Table of Contents (15) Chapters close

Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
1. Crash Course in Bash 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 1. Other Books You May Enjoy Index

Running a program continuously (forever) using looping constructs or recursion


So far, this cookbook has mostly shown scripts that serve a single purpose and exit upon task completion. This is great for single use scripts, but what about if we wanted to have scripts execute multiple scripts through a menu, or perform tasks in the background automatically forever without being executed each time by scheduling processes (like cron)? This recipe introduces a few ways for a script to run forever until it is killed or exits.

Getting ready

Besides having a terminal open, we need to remember a few concepts:

  • Recursive functions combined with a prompt (for example, the read command) can result in a script that loops based on user input
  • Looping constructs such as for, while, and until can be executed in such a way that a condition is never met and cannot exit

Therefore, a loop or something that causes a loop will force a program to run for an indefinite period of time until an exit event occurs.

Note

In...

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 €14.99/month. Cancel anytime}