玩转Go命令行工具Cobra

$ APPNAME Command Args --Flags 
# 或者
$ APPNAME Command --Flags Args

go install github.com/spf13/cobra-cli@latest

go get -u github.com/spf13/cobra@latest

package main

import "go-cobra/cmd"

func main() {
   cmd.Execute()
}

package cmd

import (
   "os"

   "github.com/spf13/cobra"
)

// rootCmd represents the base command when called without any subcommands
var rootCmd = &cobra.Command{
   Use:   "go-cobra",
   Short: "A brief description of your application",
   Long: `A longer description that spans multiple lines and likely contains
examples and usage of using your application. For example:

Cobra is a CLI library for Go that empowers applications.
This application is a tool to generate the needed files
to quickly create a Cobra application.`,
   // Uncomment the following line if your bare application
   // has an action associated with it:
   // Run: func(cmd *cobra.Command, args []string) { },
}

// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
   err := rootCmd.Execute()
   if err != nil {
      os.Exit(1)
   }
}

func init() {
   // Here you will define your flags and configuration settings.
   // Cobra supports persistent flags, which, if defined here,
   // will be global for your application.

   // rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.go-cobra.yaml)")

   // Cobra also supports local flags, which will only run
   // when this action is called directly.
   rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
}

package cmd

import (
   "fmt"
   "github.com/spf13/cobra"
   "os"
)

var name string

var rootCmd = &cobra.Command{
   Use: "hello",
   Run: func(cmd *cobra.Command, args []string) {
      fmt.Println("hello ", name)
   },
}

func Execute() {
   err := rootCmd.Execute()
   if err != nil {
      os.Exit(1)
   }
}

func init() {
   rootCmd.Flags().StringVarP(&name, "name", "", "world", "")
}

$ go build

$ .\go-cobra.exe --name zs
hello  zs

$ .\go-cobra.exe
hello  world

cobra-cli add hi

package cmd

import (
   "fmt"
   "github.com/spf13/cobra"
)

var (
   age     int
   like    []string
   address string
)

var hiCmd = &cobra.Command{
   Use:   "hi",
   Short: "",
   Long:  "",
   Run: func(cmd *cobra.Command, args []string) {
      Print()
   },
}

func init() {
   rootCmd.AddCommand(hiCmd)
   hiCmd.Flags().StringVarP(&name, "name", "", "world", "")
   hiCmd.Flags().IntVarP(&age, "age", "", 1, "")
   hiCmd.Flags().StringSliceVarP(&like, "like", "", []string{}, "")
   hiCmd.Flags().StringVarP(&address, "address", "", "Beijing", "")
}

func Print() {
   fmt.Println("name:", name)
   fmt.Println("age:", age)
   fmt.Println("like:", like)
   fmt.Println("address:", address)
}

...
var hiCmd = &cobra.Command{
   Use:   "hi",
   Short: "sss",
   Long:  "lll",
   Run: func(cmd *cobra.Command, args []string) {
      if len(args) == 0 {
         cmd.Help()
         return
      }
      Print()
   },
}
...

$ .\go-cobra.exe hi                                                             
Usage:
  hello hi [flags]


Usage:
  hello hi [flags]

Flags:
      --address string    (default "Beijing")
      --age int           (default 1)
  -h, --help             help for hi
      --like strings
      --name string       (default "world")