[TOC] > [alecthomas/kingpin](https://github.com/alecthomas/kingpin) ## 概述 * 功能比flag庫強大，用法差不多。 * 相比flag庫，最重要的一點就是支持不加"-"的調用。 ## 實例 ### 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) } ``` 輸出 ``` $ ping --help usage: ping [<flags>] <ip> [<count>] Flags: --debug Enable debug mode. --help Show help. -t, --timeout=5s Timeout waiting for ping. Args: <ip> IP address to ping. [<count>] Number of packets to send $ ping 1.2.3.4 5 Would ping: 1.2.3.4 with timeout 5s and count 5 ```