命令行应用之cobra

1、文件目录

2、代码

主要分为两步：

　 1)定义子命令

　　wordCmd = &cobra.Command{。。。。。。}
　2）将子命令添加进根命令

　　rootCmd.AddCommand(wordCmd)

cmd/word.go

package cmd

import (
	"log"
	"strings"

	cobra "github.com/spf13/cobra"
	"flag/internal/word"
)

const (
	ModeUpper                      = iota + 1 // 全部转大写
	ModeLower                                 // 全部转小写
	ModeUnderscoreToUpperCamelCase            // 下划线转大写驼峰
	ModeUnderscoreToLowerCamelCase            // 下线线转小写驼峰
	ModeCamelCaseToUnderscore                 // 驼峰转下划线
)

var str string
var mode int8

var desc = strings.Join([]string{
	"该子命令支持各种单词格式转换，模式如下：",
	"1：全部转大写",
	"2：全部转小写",
	"3：下划线转大写驼峰",
	"4：下划线转小写驼峰",
	"5：驼峰转下划线",
}, "\n")

var wordCmd = &cobra.Command{
	Use:   "word",
	Short: "单词格式转换",
	Long:  desc,
	Run: func(cmd *cobra.Command, args []string) {
		var content string
		switch mode {
		case ModeUpper:
			content = word.ToUpper(str)
		case ModeLower:
			content = word.ToLower(str)
		case ModeUnderscoreToUpperCamelCase:
			content = word.UnderscoreToUpperCamelCase(str)
		case ModeUnderscoreToLowerCamelCase:
			content = word.UnderscoreToLowerCamelCase(str)
		case ModeCamelCaseToUnderscore:
			content = word.CamelCaseToUnderscore(str)
		default:
			log.Fatalf("暂不支持该转换模式，请执行 help word 查看帮助文档")
		}

		log.Printf("输出结果: %s", content)
	},
}

func init() {
	wordCmd.Flags().StringVarP(&str, "str", "s", "", "请输入单词内容")
	wordCmd.Flags().Int8VarP(&mode, "mode", "m", 0, "请输入单词转换的模式")
}

cmd/root.go

package cmd

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

var rootCmd = &cobra.Command{}

func Execute() error {
	return rootCmd.Execute()
}

func init() {
	rootCmd.AddCommand(wordCmd)
}

word/word.go

package word

import (
	"strings"
	"unicode"
)

func ToUpper(s string) string {
	return strings.ToUpper(s)
}

func ToLower(s string) string {
	return strings.ToLower(s)
}

func UnderscoreToUpperCamelCase(s string) string {
	s = strings.Replace(s, "_", " ", -1)
	s = strings.Title(s)
	return strings.Replace(s, " ", "", -1)
}

func UnderscoreToLowerCamelCase(s string) string {
	s = UnderscoreToUpperCamelCase(s)
	return string(unicode.ToLower(rune(s[0]))) + s[1:]
}

func CamelCaseToUnderscore(s string) string {
	var output []rune
	for i, r := range s {
		if i == 0 {
			output = append(output, unicode.ToLower(r))
			continue
		}
		if unicode.IsUpper(r) {
			output = append(output, '_')
		}
		output = append(output, unicode.ToLower(r))
	}
	return string(output)
}

main.go

package main

import (
	"log"

	"flag/cmd"
)

var name string

func main() {
	err := cmd.Execute()
	if err != nil {
		log.Fatalf("cmd.Execute err: %v", err)
	}
}