nodejs实现日志读取、日志查找及日志刷新的方法分析

 function readLog(date,type，operation){ //函数接受3个参数，日期、精度(天时分秒)和操作（查找、刷新或者默认） if(date){ //如果有时间参数则对时间参数进行处理（一般日志名称都是时间加类型） var dataStr = arguments[0]; var date = dataStr.slice(0,10); var hour = dataStr.slice(11,13); var minute = dataStr.slice(11,16); var second =dataStr.slice(11,19); var type = arguments[1]; //获取精度 }else{ //若无时间参数则获取当前时间，然后精度默认 var date = new Date(+new Date()+8*3600*1000).toISOString().replace(/T/g,' ').replace(/\.[\d]{3}Z/,'').slice(0,10); var type=null; } var op = arguments[2]; var countResult = 0; //对日志结果进行统计 var logPath = appDirName.slice(0,-3)+'log\\'+'ivsvr_'+date+'.log'; //拼接日志文件名称 var logStr = ''; fs.stat(logPath, function (err, stats) { //获取对应的日志文件状态 if(err){ //日志不存在或者异常处理信息 $('#logTipInfo tr td').html('无日志信息可供查看'); console.log(err); }else{ var lineCount = 0; var readline = require('readline'); var fReadName = logPath; var fRead = fs.createReadStream(fReadName); var objReadline = readline.createInterface({ input: fRead, }); //按行读取日志 objReadline.on('line', (line)=>{ var itemStr = $.trim(line); var time = itemStr.slice(0,19); var content = itemStr.substr(20); if(!time || !content){return;} ++ lineCount; //计数行数 var matched = true; var itemStr = $.trim(line); var itemArr = itemStr.split(' '); var logDate = itemArr[0]; var logTime = itemArr[1]; var time = logDate+' '+logTime; switch(type){ //进度查找过滤 case '0': case null: matched = true; break; case '1': var timeSplit = logTime.slice(0,2); if(timeSplit == hour){ matched = true; break; } matched = false; break; case '2': var timeSplit = logTime.slice(0,5); if(timeSplit == minute){ matched = true; break; } matched = false; break; case '3': var timeSplit = logTime.slice(0,8); if(timeSplit == second){ matched = true; break; } matched = false; break; default: console.log('unkonw type!'); break; } if(matched === true &&(lineCount>logReadFlag)){ //日志结果格式化输出呈现 countResult ++; var result = itemArr[2]; if(result == 'err'){ var operation = itemArr[4]; result = '失败：'+itemArr[5]+' '+(itemArr[6]?itemArr[6]:''); }else{ var operation = itemArr[4]+' '+itemArr[5]+(itemArr[6]?itemArr[6]:''); result = '成功'; } logStr += ''+time+''+operation+''+result+'' } logStr += ''+time+''+content+'' }); objReadline.on('close', ()=>{ if(logReadFlag == 0 && (logStr == '')){ var info = '无日志信息可供查看'; } if(logReadFlag >0 && (logStr != '')){ var newLogNum = lineCount - logReadFlag; var info = '刷新成功,更新'+newLogNum+'条日志!'; $('#logInfoTable').prepend(logStr); }else if(logReadFlag >0 && (logStr == '')){ var info = '刷新成功,无日志更新!'; }else{ $('#logInfoTable').html(logStr); } if(op == 'search'){ var info = '查找到'+countResult+'条日志'; } $('#logTipInfo tr td').html(info); if((op == 'search' || op == 'refresh') &&(logReadFlag != 0 || newLogNum >0 || countResult >0)){ setTimeout(function() {$('#logTipInfo').fadeOut(567);}, 2000); //操作结束后给出信息反馈，反馈自动淡出消失 } else{ $('#logTipInfo').hide(); } logReadFlag = lineCount; console.log('closed'); }); } }); }