Golang中基础的命令行模块urfave/cli的用法说明

package main 
import (
 "github.com/urfave/cli"
 "os"
 "log"
 "fmt"
)
 
func main() {
 //实例化一个命令行程序
 oApp := cli.NewApp()
 //程序名称
 oApp.Name = "GoTool"
 //程序的用途描述
 oApp.Usage = "To save the world"
 //程序的版本号
 oApp.Version = "1.0.0"
 //该程序执行的代码
 oApp.Action = func(c *cli.Context) error {
 fmt.Println("Test")
 return nil
 }
 //启动
 if err := oApp.Run(os.Args); err != nil {
 log.Fatal(err)
 }
 /*
 result:
 [root@localhost cli]# go run main.go help
 
 NAME:
 GoTool - To save the world
 
 USAGE:
 main [global options] command [command options] [arguments...]
 
 VERSION:
 1.0.0
 
 COMMANDS:
 help, h Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
 --help, -h  show help
 --version, -v print the version
 
 [root@localhost cli]# go run main.go 
 Test
 */ 
}

package main 
import (
 "github.com/urfave/cli"
 "os"
 "log"
 "fmt"
)
 
func main() {
 //实例化一个命令行程序
 oApp := cli.NewApp()
 //程序名称
 oApp.Name = "GoTool"
 //程序的用途描述
 oApp.Usage = "To save the world"
 //程序的版本号
 oApp.Version = "1.0.0"
 
 //预置变量
 var host string
 var debug bool
 
 //设置启动参数
 oApp.Flags = []cli.Flag{
 //参数类型string,int,bool
 cli.StringFlag{
 Name:  "host",   //参数名字
 Value:  "127.0.0.1",  //参数默认值
 Usage:  "Server Address", //参数功能描述
 Destination: &host,   //接收值的变量
 },
 cli.IntFlag{
 Name:  "port,p",
 Value:  8888,
 Usage:  "Server port",
 },
 cli.BoolFlag{
 Name:  "debug",
 Usage:  "debug mode",
 Destination: &debug,
 },
 }
 
 //该程序执行的代码
 oApp.Action = func(c *cli.Context) error {
 fmt.Printf("host=%v \n",host)
 fmt.Printf("host=%v \n",c.Int("port")) //不使用变量接收，直接解析
 fmt.Printf("host=%v \n",debug)
 /*
 result:
 [root@localhost cli]# go run main.go --port 7777
 host=127.0.0.1 
 host=7777 
 host=false 
 
 [root@localhost cli]# go run main.go help
 NAME:
  GoTool - To save the world
 
 USAGE:
  main [global options] command [command options] [arguments...]
 
 VERSION:
  1.0.0
 
 COMMANDS:
 help, h Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
  --host value   Server Address (default: "127.0.0.1")
  --port value, -p value Server port (default: 8888)
  --debug     debug mode
  --help, -h    show help
  --version, -v   print the version
 */
 return nil
 }
 //启动
 if err := oApp.Run(os.Args); err != nil {
 log.Fatal(err)
 } 
}

package main 
import (
 "github.com/urfave/cli"
 "os"
 "log"
 "fmt"
)
 
func main() {
 //实例化一个命令行程序
 oApp := cli.NewApp()
 //程序名称
 oApp.Name = "GoTool"
 //程序的用途描述
 oApp.Usage = "To save the world"
 //程序的版本号
 oApp.Version = "1.0.0"
 
 //设置多个命令处理函数
 oApp.Commands = []cli.Command{
 {
 //命令全称
 Name:"lang",
 //命令简写
 Aliases:[]string{"l"},
 //命令详细描述
 Usage:"Setting language",
 //命令处理函数
 Action: func(c *cli.Context) {
 // 通过c.Args().First()获取命令行参数
 fmt.Printf("language=%v \n",c.Args().First())
 },
 },
 {
 Name:"encode",
 Aliases:[]string{"e"},
 Usage:"Setting encoding",
 Action: func(c *cli.Context) {
 fmt.Printf("encoding=%v \n",c.Args().First())
 },
 },
 }
 
 //启动
 if err := oApp.Run(os.Args); err != nil {
 log.Fatal(err)
 }
 
 /*
 [root@localhost cli]# go run main.go l english
 language=english 
 
 [root@localhost cli]# go run main.go e utf8
 encoding=utf8 
 
 [root@localhost cli]# go run main.go help
 NAME:
 GoTool - To save the world
 
 USAGE:
 main [global options] command [command options] [arguments...]
 
 VERSION:
 1.0.0
 
 COMMANDS:
 lang, l Setting language
 encode, e Setting encoding
 help, h Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
 --help, -h  show help
 --version, -v print the version
 */ 
}

package main
import (
 "os"
 "github.com/urfave/cli/v2"
 "fmt"
)
func main() {
 app := &cli.App{
 Name: "greet",
 Usage: "say a greeting",
 Action: func(c *cli.Context) error {
 fmt.Println("Greetings")
 return nil
 },
 }
 // 接受os.Args启动程序
 app.Run(os.Args)
}

var daemonStopCmd = &cli.Command{
 Name: "stop",
 Usage: "Stop a running lotus daemon",
 Flags: []cli.Flag{},
 Action: func(cctx *cli.Context) error {
 panic("wombat attack")
 },
}
func main() {
 app := &cli.App{
 Name: "greet",
 Usage: "say a greeting",
 Action: func(c *cli.Context) error {
 fmt.Println("Greetings")
 return nil
 },
 Subcommands: []*cli.Command{
 daemonStopCmd,
 },
 }
 // 接受os.Args启动程序
 app.Run(os.Args)
}