cli.go is simple, fast, and fun package for building command line apps in Go. The goal is to enable developers to write fast and distributable command line applications in an expressive way.
Command line apps are usually so tiny that there is absolutely no reason why your code should *not* be self-documenting. Things like generating help text and parsing command flags/options should not hinder productivity when writing a command line app.
This is where cli.go comes into play. cli.go makes command line programming fun, organized, and expressive!
One of the philosophies behind cli.go is that an API should be playful and full of discovery. So a cli.go app can be as little as one line of code in `main()`.
``` go
package main
import "os"
import "github.com/codegangsta/cli"
func main() {
cli.NewApp().Run(os.Args)
}
```
This app will run and show help text, but is not very useful. Let's give an action to execute and some help documentation:
``` go
package main
import "os"
import "github.com/codegangsta/cli"
func main() {
app := cli.NewApp()
app.Name = "boom"
app.Usage = "make an explosive entrance"
app.Action = func(c *cli.Context) {
println("boom! I say!")
}
app.Run(os.Args)
}
```
Running this already gives you a ton of functionality, plus support for things like subcommands and flags, which are covered below.
Being a programmer can be a lonely job. Thankfully by the power of automation that is not the case! Let's create a greeter app to fend off our demons of loneliness!
