This amazing chapter talked about many interesting topics including reading files, writing to files, and the use of the flag package, Nevertheless, there are many more topics related to systems programming not mentioned in this chapter, such as working with directories, copying, deleting, and renaming files, dealing with Unix users, groups and Unix processes, working with environment variables such as PATH, changing Unix file permissions, generating sparse files, reading and saving JSON data, locking and creating files, using and rotating your own log files, as well as the information found in the structure returned by the os.Stat() call.

At the end of this chapter, we presented two advanced utilities written in Go. The first one allowed you to inspect the state of the registers, while the second one showed you a technique that allows you to trace the system calls of any program.

I am pretty sure that the next chapter will also astonish you, as it talks about goroutines, channels, and pipelines, which are unique and powerful Go features.