Hello World in Go

hello.go

package main

import (
    "os"
    "fmt"
    "path/filepath"
)

const version = "0.1.0"

func main() {

    if len(os.Args) > 1 {
        switch os.Args[1] {
        case "-v", "--version":
            Version()
        case "-h", "--help":
            Usage()
        default:
            Usage()
        } 
    } else {
        Usage()
    }
    
}

func Version() {
    fmt.Println(filepath.Base(os.Args[0]), "version", version)
    os.Exit(0)
}

func Usage() {
    fmt.Println("Usage:", filepath.Base(os.Args[0]), "[options]")
    fmt.Println("Options:")
    fmt.Println("  -v, --version    Print version information and exit")
    fmt.Println("  -h, --help       Print this message and exit")
    os.Exit(0)
}