kingpin 简单强大命令行
最后更新于：2022-04-02 02:39:04
[TOC]
> [alecthomas/kingpin](https://github.com/alecthomas/kingpin)
## 概述
* 功能比flag库强大，用法差不多。
* 相比flag库，最重要的一点就是支持不加"-"的调用。
## 实例
### hello world
```
package main
import (
"fmt"
"gopkg.in/alecthomas/kingpin.v2"
)
var (
debug = kingpin.Flag("debug", "Enable debug mode.").Bool()
timeout = kingpin.Flag("timeout", "Timeout waiting for ping.").Default("5s").OverrideDefaultFromEnvar("PING_TIMEOUT").Short('t').Duration()
ip = kingpin.Arg("ip", "IP address to ping.").Required().IP()
count = kingpin.Arg("count", "Number of packets to send").Int()
)
func main() {
kingpin.Version("0.0.1")
kingpin.Parse()
fmt.Printf("Would ping: %s with timeout %s and count %d\n", *ip, *timeout, *count)
}
```
输出
```
$ ping --help
usage: ping [] []
Flags:
--debug Enable debug mode.
--help Show help.
-t, --timeout=5s Timeout waiting for ping.
Args:
IP address to ping.
[] Number of packets to send
$ ping 1.2.3.4 5
Would ping: 1.2.3.4 with timeout 5s and count 5
```
';