1. Install

1. go mod init hello-cli
2. go get -u github.com/spf13/cobra

2. Init Project

1. cobra-cli init
2. cobra-cli add greetgl

3. Write a application code(update cmd/greet.go)

1. Print Hello World
2. Print Hello ${name}, default name is World
3. (Print Hello ${name}, default name is World) * ${count}, default count is 1

4. Results

5. Write the makefile