Book Image

Hands-On System Programming with Go

By : Alex Guerrieri
Book Image

Hands-On System Programming with Go

By: Alex Guerrieri

Overview of this book

System software and applications were largely created using low-level languages such as C or C++. Go is a modern language that combines simplicity, concurrency, and performance, making it a good alternative for building system applications for Linux and macOS. This Go book introduces Unix and systems programming to help you understand the components the OS has to offer, ranging from the kernel API to the filesystem. You'll then familiarize yourself with Go and its specifications. You'll also learn how to optimize input and output operations with files and streams of data, which are useful tools in building pseudo-terminal applications. You'll gain insights into how processes communicate with each other, and learn about processes and daemon control using signals, pipes, and exit codes. This book will also enable you to understand how to use network communication using various protocols, including TCP and HTTP. As you advance, you'll focus on Go's best feature - concurrency, which will help you handle communication with channels and goroutines, other concurrency tools to synchronize shared resources, and the context package to write elegant applications. By the end of this book, you will have learned how to build concurrent system applications using Go
Table of Contents (24 chapters)
Free Chapter
Section 1: An Introduction to System Programming and Go
Section 2: Advanced File I/O Operations
Section 3: Understanding Process Communication
Section 4: Deep Dive into Concurrency
Section 5: A Guide to Using Reflection and CGO

Reading from files

Getting the contents of a file can be done with an auxiliary function in the io/ioutil package, as well as with the  ReadFile function, which opens, reads, and closes the file at once. This uses a small buffer (512 bytes) and loads the whole content in memory. This is not a good idea if the file size is very large, unknown, or if the content of the file can be processed one part at a time. 

Reading a huge file from disk at once means copying all the file's content into the primary memory, which is a limited resource. This can cause memory shortages, as well as runtime errors. Reading chunks of a file at a time can help read the content of big files without causing huge memory usage. This is because the same part of the memory will be reused when reading the next chunk.

An example of reading all the content at once is shown...