sample.go

package cmd

import (
        "errors"	
	"fmt"
	"io"
	"os"

	"github.com/spf13/cobra"
)

func NewCommandSample(out, errOut io.Writer) *cobra.Command {
	cmd := &cobra.Command{
		Use:   "sample",
		Short: "A brief description of your command",
		Run: func(cmd *cobra.Command, args []string) {
			if err := RunSample(out, errOut, cmd, args); err != nil {
				fmt.Fprint(errOut, "Failed to execute cmd: ", err)
				os.Exit(1)
			}
		},
	}
	return cmd
}

func init() {
	out := os.Stdout
	errOut := os.Stderr

	RootCmd.AddCommand(NewCommandSample(out, errOut))
}

func RunSample(out, errOut io.Writer, cmd *cobra.Command, args []string) error {
	if len(args) < 1 {
		return errors.New("Wrong number of arguments\n")
	}

	if args[0] != "hiyosi" {
		return fmt.Errorf("unexpected arguments specified: %v", args[0])
	}

	fmt.Fprintf(out, "Hello %v, This is a sample", args[0])

	return nil
}