为啥是Websocket
- 服务端可以主动推送消息到浏览器端。比如服务端实时在打印日志，这是一个标准输出，可以实时将日志推送到浏览器。
为啥用websocketd (https://github.com/joewalnes/websocketd)
- 后台脚本不限语言，标准输入（stdin）就是 WebSocket 的输入，标准输出（stdout）就是 WebSocket 的输出。(http://www.ruanyifeng.com/blog/2017/05/websocket.html)
举例
- 定时打印当前时间
import datetime,timefrom sys import stdoutwhile True: ???now = time.strftime("%Y-%m-%d %H:%M:%S") ???print now ???stdout.flush() ???time.sleep(2)- 这是标准输出
root@ubuntu:~# python test.py 2018-12-17 09:57:372018-12-17 09:57:392018-12-17 09:57:412018-12-17 09:57:432018-12-17 09:57:452018-12-17 09:57:47- 启动websocketd
root@ubuntu:~# websocketd --port=9000 ?python test.py - 浏览器连接websocketd服务
<!DOCTYPE html><html> ?<head> ???<title>websocketd ?example</title> ???<style> ?????#count { ???????font: bold 150px arial; ???????margin: auto; ???????padding: 10px; ???????text-align: center; ?????} ???</style><script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script> ?</head> ?<body><table border="1px #ooo" id="logtable" cellpadding="0" ??cellspacing="0" width="30%"> ??<tr align="center"> ???<td width="100%">log</td> ???</tr> ??</table> ???<script> ?????function addTr(tab, row, trHtml){ ????????var $tr=$("#"+tab+" tr").eq(row); ????????if($tr.size()==0){ ???????alert("id not exit"); ???????return; ????????} ????????$tr.after(trHtml); ?????}; ??????????//addTr(‘logtable‘, -1, ‘xxxxxxxxxx‘); ??????var ws = new WebSocket(‘ws://‘ + (location.host ? location.host : "localhost:9000") + "/"); ?????ws.onopen = function() { ???????document.body.style.backgroundColor = ‘#cfc‘; ?????}; ?????ws.onclose = function() { ???????document.body.style.backgroundColor = null; ?????}; ?????ws.onmessage = function(event) { ??????console.log(event.data); ???????//document.getElementById(‘count‘).textContent = event.data; ???????addTr(‘logtable‘, -1, ‘<tr><td>‘ + ?event.data + ‘</td></tr>‘) ?????}; ???</script> ?</body></html>- 效果图
技巧之如何快速使用websocket来监控标准输出
原文地址：https://www.cnblogs.com/xiaoxiaoleo/p/10134914.html