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
Linux System Programming Techniques

You're reading from   Linux System Programming Techniques Become a proficient Linux system programmer using expert recipes and techniques

Arrow left icon
Product type Paperback
Published in May 2021
Publisher Packt
ISBN-13 9781789951288
Length 432 pages
Edition 1st Edition
Tools
Arrow right icon
Author (1):
Arrow left icon
Jack-Benny Persson Jack-Benny Persson
Author Profile Icon Jack-Benny Persson
Jack-Benny Persson
Arrow right icon
View More author details
Toc

Table of Contents (14) Chapters Close

Preface 1. Chapter 1: Getting the Necessary Tools and Writing Our First Linux Programs 2. Chapter 2: Making Your Programs Easy to Script FREE CHAPTER 3. Chapter 3: Diving Deep into C in Linux 4. Chapter 4: Handling Errors in Your Programs 5. Chapter 5: Working with File I/O and Filesystem Operations 6. Chapter 6: Spawning Processes and Using Job Control 7. Chapter 7: Using systemd to Handle Your Daemons 8. Chapter 8: Creating Shared Libraries 9. Chapter 9: Terminal I/O and Changing Terminal Behavior 10. Chapter 10: Using Different Kinds of IPC 11. Chapter 11: Using Threads in Your Programs 12. Chapter 12: Debugging Your Programs 13. Other Books You May Enjoy

Reading and writing binary data with streams

There comes a time when we must save variables or arrays in a program to a file. For example, if we make a stock-keeping program for a warehouse, we don't want to re-write the entire warehouse stocks every time we start the program. That would defeat the purpose of the program. With streams, it's easy to save variables as binary data in files for later retrieval.

In this chapter, we'll write two small programs: one that asks the user for two floats, saves them in an array, and writes them to a file, and another program that re-reads that array.

Getting ready

You only need the GCC compiler, the Make tool, and the generic Makefile for this recipe.

How to do it…

In this recipe, we'll write two small programs: one that writes and one that reads binary data. The data is an array of floats:

  1. Write the following code in a file and save it as binary-write.c. Notice that we open the file in write mode...
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