Go Tutorial

Installation

We can go to https://golang.org/dl/ and download the binary depending on our Operating System and install it. Once installed run go version and you should be able to see the go version.

$ go version
go version go1.21.6 darwin/amd64
$

Once go is installed set GOPATH environment variable. On MacOS by default it is set to ${user.home}/go. We can also add $GOPATH/bin to our PATH.

$ export GOPATH=~/go
$ export PATH=$PATH:$GOPATH/bin

Quickstart

Create New Project

Create a new project directory hello-go and cd into the directory:

$ mkdir hello-go & cd hello-go

In hello-go directory create hello.go as follows:

hello.go

package main

import "fmt"

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

Now you can run the application using go run hello.go and build the application as executable binary using go build as follows:

hello-go> go run hello.go
Hello World!!!
hello-go> go build
hello-go> ls
hello hello.go
hello-go> ./hello
Hello World!!!

We can initialize the hello-go application as a module using go mod init command as follows:

hello-go> go mod init github.com/sivaprasadreddy/hello-go
go: creating new go.mod: module github.com/sivaprasadreddy/hello-go
hello-go> cat go.mod
module github.com/sivaprasadreddy/hello-go

go 1.21
hello-go>

We can install 3rd-party dependencies using go get command as follows:

hello-go> go get -u github.com/mitchellh/go-homedir
hello-go> cat go.mod
module github.com/sivaprasadreddy/hello-go

go 1.21

require github.com/mitchellh/go-homedir v1.1.0 // indirect
hello-go>

We can use homedir module as follows:

hello.go

package main

import (
    "fmt"
    "github.com/mitchellh/go-homedir"
    "os"
)

func main()  {
    fmt.Println("Hello World!!!")
    home, err := homedir.Dir()
    if err != nil {
        fmt.Println("Error: ", err)
        os.Exit(1)
    }
    fmt.Println("My Home directory: ", home)
}