Golang之使用Cobra

type Command struct {
    Use string // The one-line usage message.
    Short string // The short description shown in the 'help' output.
    Long string // The long message shown in the 'help <this-command>' output.
    Run func(cmd *Command, args []string) // Run runs the command.
}

import "github.com/spf13/cobra"

package main

import (
  "fmt"
  "os"

  "{pathToYourApp}/cmd"
)

func main() {
  if err := cmd.RootCmd.Execute(); err != nil {
    fmt.Println(err)
    os.Exit(1)
  }
}

package cmd

import (
	"fmt"
	"os"

	"github.com/mitchellh/go-homedir"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var RootCmd = &cobra.Command{
	Use:     "chenjian",
	Aliases: []string{"cj", "ccccjjjj"},
	Short:   "call me jack",
	Long: `A Fast and Flexible Static Site Generator built with
                love by spf13 and friends in Go.
                Complete documentation is available at https://o-my-chenjian.com`,
	Run: func(cmd *cobra.Command, args []string) {
		fmt.Printf("OK")
	},
}

var cfgFile, projectBase, userLicense string

func init() {
	cobra.OnInitialize(initConfig)

	// 在此可以定义自己的flag或者config设置，Cobra支持持久标签(persistent flag)，它对于整个应用为全局
	// 在StringVarP中需要填写`shorthand`，详细见pflag文档
	RootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (defalut in $HOME/.cobra.yaml)")
	RootCmd.PersistentFlags().StringVarP(&projectBase, "projectbase", "b", "", "base project directory eg. github.com/spf13/")
	RootCmd.PersistentFlags().StringP("author", "a", "YOUR NAME", "Author name for copyright attribution")
	RootCmd.PersistentFlags().StringVarP(&userLicense, "license", "l", "", "Name of license for the project (can provide `licensetext` in config)")
	RootCmd.PersistentFlags().Bool("viper", true, "Use Viper for configuration")

	// Cobra同样支持局部标签(local flag)，并只在直接调用它时运行
	RootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")

	// 使用viper可以绑定flag
	viper.BindPFlag("author", RootCmd.PersistentFlags().Lookup("author"))
	viper.BindPFlag("projectbase", RootCmd.PersistentFlags().Lookup("projectbase"))
	viper.BindPFlag("useViper", RootCmd.PersistentFlags().Lookup("viper"))
	viper.SetDefault("author", "NAME HERE <EMAIL ADDRESS>")
	viper.SetDefault("license", "apache")
}

func Execute()  {
	RootCmd.Execute()
}

func initConfig() {
	// 勿忘读取config文件，无论是从cfgFile还是从home文件
	if cfgFile != "" {
		viper.SetConfigName(cfgFile)
	} else {
		// 找到home文件
		home, err := homedir.Dir()
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		// 在home文件夹中搜索以“.cobra”为名称的config
		viper.AddConfigPath(home)
		viper.SetConfigName(".cobra")
	}
	// 读取符合的环境变量
	viper.AutomaticEnv()

	if err := viper.ReadInConfig(); err != nil {
		fmt.Println("Can not read config:", viper.ConfigFileUsed())
	}
}

package main

import (
	"fmt"
	"os"

	"cjappmanu/cmd"
)

func main() {
	if err := cmd.RootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

package cmd

import (
	"fmt"

	"github.com/spf13/cobra"
)

func init() {
	RootCmd.AddCommand(versionCmd)
}

var versionCmd = &cobra.Command{
	Use:   "version",
	Short: "Print the version number of ChenJian",
	Long:  `All software has versions. This is Hugo's`,
	Run: func(cmd *cobra.Command, args []string) {
		fmt.Println("Chen Jian Version: v1.0 -- HEAD")
	},
}

RootCmd.AddCommand(versionCmd)

RootCmd.PersistentFlags().BoolVarP(&Verbose, "verbose", "v", false, "verbose output")

RootCmd.Flags().StringVarP(&Source, "source", "s", "", "Source directory to read from")

var author string

func init() {
  RootCmd.PersistentFlags().StringVar(&author, "author", "YOUR NAME", "Author name for copyright attribution")
  viper.BindPFlag("author", RootCmd.PersistentFlags().Lookup("author"))
}

var cmd = &cobra.Command{
  Short: "hello",
  Args: func(cmd *cobra.Command, args []string) error {
    if len(args) < 1 {
      return errors.New("requires at least one arg")
    }
    if myapp.IsValidColor(args[0]) {
      return nil
    }
    return fmt.Errorf("invalid color specified: %s", args[0])
  },
  Run: func(cmd *cobra.Command, args []string) {
    fmt.Println("Hello, World!")
  },
}

package cmd

import (
	"fmt"
	"os"
	"strings"

	homedir "github.com/mitchellh/go-homedir"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var cfgFile string
var echoTimes int

var RootCmd = &cobra.Command{
	Use: "app",
}

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 [string to echo]",
	Short: "Echo anything to the screen",
	Long: `echo is for echoing anything back.
Echo works a lot like print, except it has a child command.`,
	Args: cobra.MinimumNArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		fmt.Println("Print: " + strings.Join(args, " "))
	},
}

var cmdTimes = &cobra.Command{
	Use:   "times [# 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, " "))
		}
	},
}

func init() {
	cobra.OnInitialize(initConfig)

	cmdTimes.Flags().IntVarP(&echoTimes, "times", "t", 1, "times to echo the input")

	// 两个顶层的命令，和一个cmdEcho命令下的子命令cmdTimes
	RootCmd.AddCommand(cmdPrint, cmdEcho)
	cmdEcho.AddCommand(cmdTimes)
}

func Execute() {
	RootCmd.Execute()
}

func initConfig() {
	// 勿忘读取config文件，无论是从cfgFile还是从home文件
	if cfgFile != "" {
		viper.SetConfigName(cfgFile)
	} else {
		// 找到home文件
		home, err := homedir.Dir()
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		// 在home文件夹中搜索以“.cobra”为名称的config
		viper.AddConfigPath(home)
		viper.SetConfigName(".cobra")
	}
	// 读取符合的环境变量
	viper.AutomaticEnv()

	if err := viper.ReadInConfig(); err != nil {
		fmt.Println("Can not read config:", viper.ConfigFileUsed())
	}
}

func (c *Command) initHelp() {
  if c.helpCommand == nil {
    c.helpCommand = &Command{
      Use:   "help [command]",
      Short: "Help about any command",
      Long: `Help provides help for any command in the application.
        Simply type ` + c.Name() + ` help [path to command] for full details.`,
      Run: c.HelpFunc(),
    }
  }
  c.AddCommand(c.helpCommand)
}

command.SetHelpCommand(cmd *Command)
command.SetHelpFunc(f func(*Command, []string))
command.SetHelpTemplate(s string)

return func(c *Command) error {
  err := tmpl(c.Out(), c.UsageTemplate(), c)
  return err
}

command.SetUsageFunc(f func(*Command) error)

command.SetUsageTemplate(s string)

command.DisableSuggestions = true

// 或者

command.SuggestionsMinimumDistance = 1