The Go Cookbook

Running a one-off File

What's the easiest way to run a single Go file?

First steps are often both fundamental and overlooked.

Go’s unusual packaging and compilation process can be daunting and confusing to a new developer. Unlike most compiled languages, Go actually comes with a very easy way of running a single file. Simply execute the program with go run filename.go:

package main

import "fmt"

func main() {
	fmt.Println("Hello World!")
}

$ go run test_hello_world.go
Hello World!

This allows Go to act as though it were a more dynamic language, and is useful for development and exploration. However, Go’s compiler is so incredibly fast, that it’s possible to use this technique in a production setting:

$ time go run empty.go

real	0m0.103s
user	0m0.058s
sys	0m0.033s

Throughout this book, you’ll see many Go programs. Each one is available as a separate file in this book, and each example includes the go run command required to run the file along side the full output.