Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Go CookBook

You're reading from   Go CookBook Top techniques and practical solutions for real-life Go programming problems

Arrow left icon
Product type Paperback
Published in Dec 2024
Publisher Packt
ISBN-13 9781835464397
Length
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Burak Serdar Burak Serdar
Author Profile Icon Burak Serdar
Burak Serdar
Arrow right icon
View More author details
Toc

Table of Contents (20) Chapters Close

Preface 1. Chapter 1: Project Organization 2. Chapter 2: Working with Strings FREE CHAPTER 3. Chapter 3: Working with Date and Time 4. Chapter 4: Working with Arrays, Slices, and Maps 5. Chapter 5: Working with Types, Structs, and Interfaces 6. Chapter 6: Working with Generics 7. Chapter 7: Concurrency 8. Chapter 8: Errors and Panics 9. Chapter 9: The Context Package 10. Chapter 10: Working with Large Data 11. Chapter 11: Working with JSON 12. Chapter 12: Processes 13. Chapter 13: Network Programming 14. Chapter 14: Streaming Input/Output 15. Chapter 15: Databases 16. Chapter 16: Logging 17. Chapter 17: Testing, Benchmarking, and Profiling 18. Index 19. Other Books You May Enjoy

Working with files

Files are simply sequences of bytes on a storage system. There are two ways of working with files: as a random access byte sequence or as a stream of bytes. We will look at both types of recipes in this section.

Creating and opening files

To work with the contents of a file, you first have to open it or create it. This recipe shows how that can be done.

How to do it...

To open an existing file for reading, use os.Open:

file, err := os.Open(fileName)
if err!=nil {
 // handle error
}

You can read data from the returned file object, and when you are done, you should close it using file.Close(). So, you can use it as an io.Reader or io.ReadCloser (there are more interfaces that *os.File implements!)

If you attempt to write to the file, you will receive an error from the write operation. On my Linux system, this error is a *fs.PathError message saying bad file descriptor.

To create a new file or to overwrite an existing one, use os.Create:

file...
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
Banner background image