Flag和Pflag类似于python的argparse:解析命令行
flag是golang自带的包;github.com/spf13/pflag
参考:https://o-my-chenjian.com/2017/09/20/Using-Flag-And-Pflag-With-Golang/
flag是golang自带的包;github.com/spf13/pflag
参考:https://o-my-chenjian.com/2017/09/20/Using-Flag-And-Pflag-With-Golang/