内容简介：golang如何覆盖输出console，实现进度条
在研究K6源代码的时候，发现有一个进度条，觉得不错，就研究了一下怎么实现的，很简单，不说话，直接上代码
package main
import (
"fmt"
"os"
"time"
)
func main() {
for i := 0; i != 10; i = i + 1 {
fmt.Fprintf(os.Stdout, "result is %d\r", i)
time.Sleep(time.Second * 1)
}
fmt.Println("over")
}
最后输出的时候，添加\r，原理可以查看 https://stackoverflow.com/questions/15442292/golang-how-to-have-an-inplace-string-that-updates-at-stdout
stdout is a stream (io.Writer). You cannot modify what was already written to it. What can be changed is how is that stream represented in case it is printed to a terminal. Note that there’s no good reason to assume this scenario. An user can e.g. redirect stdout to a pipe or to a file at will. So the proper approach is to first check
if the stdout is going to a terminal
what is that terminal procedure to overwrite a line/a screen
Both of the above is out of this question scope, but let’s assume a terminal realy is our device. Then usually printing
fmt.Printf(“\rOn %d/10″, i)
will overwrite the previous line in the terminal. \r stands for a carriage return, implemented by many terminals as moving the cursor to the beginning of the current line, hence providing the “overwrite line” facility.
As an example of an “other” terminal with a differently supported ‘overwriting’, here is an example at the playground.
以上所述就是小编给大家介绍的《golang如何覆盖输出console，实现进度条》，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对 码农网 的支持！
本站部分资源来源于网络，本站转载出于传递更多信息之目的，版权归原作者或者来源机构所有，如转载稿涉及版权问题，请联系我们。
