The cli is a simple, fast, and fun package for building command-line applications in Go. The aim is to enable developers to write fast and distributable command-line applications in an expressive way.
github address:
https://github.com/urfave/cli Star 16.9k
Use the v2 distribution
> # go get github.com/urfave/cli/v2 Documentation:
https://github.com/urfave/cli/blob/master/docs/v2/manual.md
...
import(
"github.com/urfave/cli/v2" //导入为包"cli"
)
... Example 1:
package main
import (
"os"
"github.com/urfave/cli/v2"
)
func main() {
(&cli.App{}).Run(os.Args)
} Execution method 1:
> # go run main.go
NAME:
cli - A new cli application
USAGE:
cli [global options] command [command options] [arguments...]
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help (default: false) Execution method 2:
> # go mod init cli
> # go build
> # cli
NAME:
cli - A new cli application
USAGE:
cli [global options] command [command options] [arguments...]
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help (default: false) Execution method 3:
> # go install
> # cli
NAME:
cli - A new cli application
USAGE:
cli [global options] command [command options] [arguments...]
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help (default: false) Example 2:
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
app := &cli.App{
Name: "boom",
Usage: "make an explosive entrance",
Action: func(c *cli.Context) error {
fmt.Println("boom! I say!")
return nil
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} Execution method 1:
> # go run main.go
boom! I say! > # go run main.go --help
NAME:
cli - A new cli application
USAGE:
cli [global options] command [command options] [arguments...]
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help (default: false) Execution method 2:
> # go mod init cli
> # go build
> # cli
boom! I say! > # cli --help
NAME:
cli - A new cli application
USAGE:
cli [global options] command [command options] [arguments...]
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help (default: false) Execution method 3:
Install the command to the $GOPATH/bin directory:
> # go install
> # cli
boom! I say! Example 3:
First create a directory called greet, then add the file to it, and add the following code to greet.go:
greet.go
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
app := &cli.App{
Name: "greet",
Usage: "fight the loneliness!",
Action: func(c *cli.Context) error {
fmt.Println("Hello friend!")
return nil
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} > # go mod init greet //这里不需要 main.go 入口文件
> # go install //安装命令到 $GOPATH/bin 目录下
> # go env GOPATH
/root/go
> # /root/go/bin/greet
Hello friend! Here's a demonstration of the name and path of the compiled binary:
> # cd /home/greet/
> # mv greet.go main.go
> # go build
> # ls
go.mod go.sum greet main.go > # go build -o main
> # ls
go.mod go.sum greet main main.go
> # ./main
Hello friend! View the help information
> # ./greet --help
NAME:
greet - fight the loneliness!
USAGE:
greet [global options] command [command options] [arguments...]
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help (default: false)
> # go install
> # ls
go.mod go.sum main main.go Caution:
1 go install 安装的命令文件名称由 go mod init [module] 初始化模块的名称 [module] 决定, 安装命令存放到到 $GOPATH/bin 目录下;
2 go build is determined by go mod init [module] by default, and it is stored in the current directory by default, but you can override the path and name of the command file by -o;
3 Name and Usage are used to display help information, not to specify the name of the compiled command file;
4 go install 会自动清除go build 编译的目录文件, 除 go build -o 方式之外;
5 编译时一个目录下只能有一个 package main 定义的包名; 否则会报: main redeclared in this block previous declaration 错误信息;
Example 4: Obtain parameters
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
app := &cli.App{
Action: func(c *cli.Context) error {
fmt.Printf("Hello %q", c.Args().Get(0)) // 获取第一个参数
return nil
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} > # go build
> # ./greet xukaikai
Hello "xukaikai" Example 4: Flags
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag {
&cli.StringFlag{
Name: "lang",
Value: "english",
Usage: "language for the greeting",
},
},
Action: func(c *cli.Context) error {
name := "Nefertiti"
if c.NArg() > 0 {
name = c.Args().Get(0)
}
if c.String("lang") == "spanish" {
fmt.Println("Hola", name)
} else {
fmt.Println("Hello", name)
}
return nil
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} > # go build
> # greet
Hello Nefertiti
> # greet --lang spanish
Hola Nefertiti Example 5:
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
var language string
app := &cli.App{
Flags: []cli.Flag{
&cli.StringFlag{
Name: "lang",
Value: "english",
Usage: "language for the greeting",
Destination: &language, // 目标设置为变量
},
},
Action: func(c *cli.Context) error {
name := "someone"
if c.NArg() > 0 {
name = c.Args().Get(0)
}
if language == "spanish" {
fmt.Println("Hola", name)
} else {
fmt.Println("Hello", name)
}
return nil
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} Example 6: Use aliases
package main
import (
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag{
&cli.StringFlag{
Name: "config",
Aliases: []string{"c"}, // 设置别名
Usage: "Load configuration from `FILE`",
},
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} > # greet --help
NAME:
cli - A new cli application
USAGE:
cli [global options] command [command options] [arguments...]
COMMANDS:
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--config FILE, -c FILE Load configuration from FILE
--help, -h show help (default: false) Example 7: Multiple commands
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
app := cli.NewApp()
app.EnableBashCompletion = true
app.Commands = []*cli.Command{
{
Name: "add",
Aliases: []string{"a"},
Usage: "add a task to the list",
Action: func(c *cli.Context) error {
fmt.Println("added task: ", c.Args().First())
return nil
},
},
{
Name: "complete",
Aliases: []string{"c"},
Usage: "complete a task on the list",
Action: func(c *cli.Context) error {
fmt.Println("completed task: ", c.Args().First())
return nil
},
},
{
Name: "template",
Aliases: []string{"t"},
Usage: "options for task templates",
Subcommands: []*cli.Command{
{
Name: "add",
Usage: "add a new template",
Action: func(c *cli.Context) error {
fmt.Println("new task template: ", c.Args().First())
return nil
},
},
{
Name: "remove",
Usage: "remove an existing template",
Action: func(c *cli.Context) error {
fmt.Println("removed task template: ", c.Args().First())
return nil
},
},
},
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} > # go build
> # ./greet add 3 5
added task: 3
Example 8: The version number is displayed
package main
import (
"fmt"
"os"
"github.com/urfave/cli/v2"
)
var (
Revision = "fafafaf"
)
func main() {
cli.VersionPrinter = func(c *cli.Context) {
fmt.Printf("version=%s revision=%s\n", c.App.Version, Revision)
}
app := &cli.App{
Name: "partay",
Version: "v19.99.0",
}
app.Run(os.Args)
} > # go build
> # ./greet --verion
version=v19.99.0 revision=fafafaf Example: Use a template
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
func main() {
app := &cli.App{
Flags: []cli.Flag{
&cli.TimestampFlag{Name: "meeting", Layout: "2006-01-02T15:04:05"},
},
Action: func(c *cli.Context) error {
fmt.Printf("%s", c.Timestamp("meeting").String())
return nil
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} > # go build
> # ./greet --meeting 2019-08-12T15:04:05
2019-08-12 15:04:05 +0000 UTC Instance:
main.go
package main
import (
"fmt"
"log"
"os"
"github.com/urfave/cli/v2"
)
var (
Revision = "mainnet"
)
func main() {
// 添加版本号
cli.VersionPrinter = func(c *cli.Context) {
fmt.Printf("version=%s revision=%s\n", c.App.Version, Revision)
}
app := &cli.App{
Name: "version",
Version: "v1.0.0",
}
// 此设置将允许应用程序的子命令自动完成
app.EnableBashCompletion = true
// 多重命令和子命令
app.Commands = []*cli.Command{
{
Name: "add",
Aliases: []string{"a"},
Usage: "add a task to the list",
Action: func(c *cli.Context) error {
// 获取参数
fmt.Println("added task: ", c.Args().First())
return nil
},
},
{
Name: "complete",
Aliases: []string{"c"},
Usage: "complete a task on the list",
Action: func(c *cli.Context) error {
fmt.Println("completed task: ", c.Args().First())
return nil
},
},
{
Name: "template",
Aliases: []string{"t"},
Usage: "options for task templates",
Subcommands: []*cli.Command{
{
Name: "add",
Usage: "add a new template",
Action: func(c *cli.Context) error {
fmt.Println("new task template: ", c.Args().First())
return nil
},
},
{
Name: "remove",
Usage: "remove an existing template",
Action: func(c *cli.Context) error {
fmt.Println("removed task template: ", c.Args().First())
return nil
},
},
},
},
}
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
} > # go build -o cli main.go
> # ./cli
NAME:
version - A new cli application
USAGE:
cli [global options] command [command options] [arguments...]
VERSION:
v1.0.0
COMMANDS:
add, a add a task to the list
complete, c complete a task on the list
template, t options for task templates
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--help, -h show help (default: false)
--version, -v print the version (default: false)