gosuri/uiprogress: A go library to render progress bars in terminal applications
https://github.com/gosuri/uiprogress
依赖go-isatty，用于判断程序是在什么终端运行
https://github.com/mattn/go-isatty
依赖uilive，提供一个定时刷新的命令行输出
https://github.com/gosuri/uilive
uiprogress.Start() // start rendering
bar := uiprogress.AddBar(100) // Add a new bar
// optionally, append and prepend completion and elapsed time
bar.AppendCompleted()
bar.PrependElapsed()
for bar.Incr() {
time.Sleep(time.Millisecond * 20)
}
原文：http://www.cnblogs.com/zapline/p/7753796.html