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|
---
tags:
- v2
search:
boost: 2
---
One of the philosophies behind cli is that an API should be playful and full of
discovery. So a cli app can be as little as one line of code in `main()`.
<!-- {
"args": ["--help"],
"output": "A new cli application"
} -->
```go
package main
import (
"os"
"github.com/urfave/cli/v2"
)
func main() {
(&cli.App{}).Run(os.Args)
}
```
This app will run and show help text, but is not very useful.
```
$ wl-paste > hello.go
$ go build hello.go
$ ./hello
NAME:
hello - A new cli application
USAGE:
hello [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)
```
Let's add an action to execute and some help documentation:
<!-- {
"output": "boom! I say!"
} -->
```go
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(*cli.Context) error {
fmt.Println("boom! I say!")
return nil
},
}
if err := app.Run(os.Args); err != nil {
log.Fatal(err)
}
}
```
Running this already gives you a ton of functionality, plus support for things
like subcommands and flags, which are covered below.
|
