package main import ( "fmt" "os" "strings" "github.com/pkg/errors" ) func echo(args []string) error { if len(args) < 2 { return errors.New("no message to echo") } _, err := fmt.Println(strings.Join(args[1:], " ")) return err } func main() { if err := echo(os.Args); err != nil { fmt.Fprintf(os.Stderr, "%+v\n", err) os.Exit(1) } }