Table Of ContentGo Standard Library Cookbook
Over 120 specific ways to make full use of the standard
library components in Golang
Radomír Sohlich
BIRMINGHAM - MUMBAI
Go Standard Library Cookbook
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Contributors
About the author
Radomír Sohlich received the master's degree in Applied Informatics from Faculty of
Applied Informatics at Tomas Bata University in Zlín. After that, he got a job in a start-up
company as a software developer and worked on various projects, usually based on the
Java platform. Currently, he continues a software developer career as a contractor for a
large international company.
In 2015, he fell in love with Go and kept exploring the endless power and possibilities of the
language. He is passionate about learning new approaches and technology and feels the
same about sharing the knowledge with others.
I'd like to thank my beloved wife and kids for the time they gave me for creating this book.
The next big thank you belongs to Mert Serin, who agreed to review the book and give a
feedback on the content.
About the reviewer
Mert Serin was born in Izmir in 1993, graduated from Hacettepe University in 2016, and
has worked on iOS development since his third year in university. He is currently working
at USIT Inc., a start-up based in Atlanta, GE, as a full stack developer.
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Table of Contents
Preface 1
Chapter 1: Interacting with the Environment 6
Introduction 6
Retrieving the Golang version 7
Getting ready 7
How to do it... 7
How it works... 8
Accessing program arguments 9
How to do it... 9
How it works... 10
There's more… 10
Creating a program interface with the flag package 11
How to do it... 11
How it works… 13
There's more… 14
Getting and setting environment variables with default values 14
How to do it… 14
How it works… 17
Retrieving the current working directory 18
How to do it... 18
How it works… 19
Getting the current process PID 20
How to do it… 20
How it works… 21
Handling operating system signals 21
How to do it… 22
How it works… 23
Calling an external process 24
Getting ready 24
How to do it… 25
Table of Contents
How it works… 27
See also 28
Retrieving child process information 28
Getting ready 28
How to do it… 28
How it works… 31
See also 31
Reading/writing from the child process 31
Getting ready 31
How to do it… 32
How it works… 38
Shutting down the application gracefully 39
How to do it… 39
How it works… 42
See also 42
File configuration with functional options 42
How to do it... 42
How it works... 45
Chapter 2: Strings and Things 46
Introduction 46
Finding the substring in a string 47
How to do it... 47
How it works... 48
See also 48
Breaking the string into words 49
How to do it... 49
How it works... 52
There's more... 53
Joining the string slice with a separator 53
How to do it... 53
How it works... 55
There's more... 56
Concatenating a string with writer 56
How to do it... 56
How it works... 58
[ ii ]
Table of Contents
There's more... 58
Aligning text with tabwriter 59
How to do it... 60
How it works... 61
Replacing part of the string 61
How to do it... 61
How it works... 63
There's more... 64
Finding the substring in text by the regex pattern 64
How to do it... 64
How it works... 65
See also 66
Decoding a string from the non-Unicode charset 66
How to do it... 66
How it works... 68
Controlling case 69
How to do it... 69
How it works... 71
Parsing comma-separated data 71
How to do it... 72
How it works... 74
Managing whitespace in a string 75
How to do it... 75
How it works... 76
See also 77
Indenting a text document 77
How to do it... 78
How it works... 79
See also 79
Chapter 3: Dealing with Numbers 80
Introduction 80
Converting strings to numbers 81
How to do it... 81
How it works... 82
Comparing floating-point numbers 83
[ iii ]
Table of Contents
How to do it... 83
How it works... 85
Rounding floating-point numbers 86
How to do it... 86
How it works... 87
Floating-point arithmetics 88
How to do it... 88
How it works... 89
There's more... 89
See also 90
Formatting numbers 90
How to do it... 90
How it works... 92
There's more... 93
Converting between binary, octal, decimal, and hexadecimal 93
How to do it... 93
How it works... 95
Formatting with the correct plurals 95
Getting ready 95
How to do it... 95
How it works... 97
There's more... 97
Generating random numbers 98
How to do it... 98
How it works... 99
Operating complex numbers 100
How to do it... 100
How it works... 101
Converting between degrees and radians 102
How to do it... 102
How it works... 103
Taking logarithms 104
How to do it... 104
How it works... 105
Generating checksums 105
[ iv ]
