框架：cobra

package main

import (
"fmt"
"strings"

"github.com/spf13/cobra"
)

func main() {
    var echoTimes int

    var cmdPrint = &cobra.Command{
        Use:   "print [string to print]",
        Short: "Print anything to the screen",
        Long: `print is for printing anything back to the screen.
For many years people have printed back to the screen.`,
        Args: cobra.MinimumNArgs(1),
        Run: func(cmd *cobra.Command, args []string) {
            fmt.Println("Print: " + strings.Join(args, " "))
        },
    }

    var cmdEcho = &cobra.Command{
        Use:   "echo [传入参数]", // 使用方式 echo表示命令，Use的第一个单词，碰到空格结束的第一个单词
        Short: "简述",
        Long: "完整描述",
        Args: cobra.MinimumNArgs(2), // 至少n个参数
        Run: func(cmd *cobra.Command, args []string) {
            fmt.Println("Echo: " + strings.Join(args, " "))
        },
    }

    var cmdTimes = &cobra.Command{
        Use:   "times [string to echo]",
        Short: "Echo anything to the screen more times",
        Long: `echo things multiple times back to the user by providing
a count and a string.`,
        Args: cobra.MinimumNArgs(1),
        Run: func(cmd *cobra.Command, args []string) {
            for i := 0; i < echoTimes; i++ {
                fmt.Println("Echo: " + strings.Join(args, " "))
            }
        },
    }
    
    // 给times添加flag ,Flags表示当前cmd有效，本地作用域
    cmdTimes.Flags().IntVarP(&echoTimes, "times", "t", 1, "times to echo the input")

    var rootCmd = &cobra.Command{Use: "app"}
    rootCmd.AddCommand(cmdPrint, cmdEcho)
    cmdEcho.AddCommand(cmdTimes) // times 是echo的子命令
    rootCmd.Execute()
}

• 使用

test.exe echo 1 2


$ ./test.exe echo times
Error: requires at least 1 arg(s), only received 0
Usage:
  app echo times [string to echo] [flags]

Flags:
  -h, --help        help for times
  -t, --times int   times to echo the input (default 1)


$ ./test.exe echo times 1 2 --times 4
Echo: 1 2
Echo: 1 2
Echo: 1 2
Echo: 1 2

• 钩子函数

package main

import (
  "fmt"

  "github.com/spf13/cobra"
)

func main() {

  var rootCmd = &cobra.Command{
    Use:   "root [sub]",
    Short: "My root command",
    PersistentPreRun: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside rootCmd PersistentPreRun with args: %v\n", args)
    },
    PreRun: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside rootCmd PreRun with args: %v\n", args)
    },
    Run: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside rootCmd Run with args: %v\n", args)
    },
    PostRun: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside rootCmd PostRun with args: %v\n", args)
    },
    PersistentPostRun: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside rootCmd PersistentPostRun with args: %v\n", args)
    },
  }

  var subCmd = &cobra.Command{
    Use:   "sub [no options!]",
    Short: "My subcommand",
    PreRun: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside subCmd PreRun with args: %v\n", args)
    },
    Run: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside subCmd Run with args: %v\n", args)
    },
    PostRun: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside subCmd PostRun with args: %v\n", args)
    },
    PersistentPostRun: func(cmd *cobra.Command, args []string) {
      fmt.Printf("Inside subCmd PersistentPostRun with args: %v\n", args)
    },
  }

  rootCmd.AddCommand(subCmd)

  rootCmd.SetArgs([]string{""})
  rootCmd.Execute()
  fmt.Println()
  rootCmd.SetArgs([]string{"sub", "arg1", "arg2"})
  rootCmd.Execute()
}