逐行解析生成的node.js子进程的输出 [英] Parse output of spawned node.js child process line by line

问题描述

我有一个PhantomJS/CasperJS脚本，它是使用process.spawn()从node.js脚本中运行的.由于CasperJS不支持require() ing模块，因此我尝试将命令从CasperJS打印到stdout，然后使用spawn.stdout.on('data', function(data) {});从我的node.js脚本中读取它们，以进行将对象添加到redis的操作. /mongoose(令人费解，是的，但是比为此设置Web服务要简单得多.)CasperJS脚本执行一系列命令并创建例如20个屏幕快照，需要将其添加到我的数据库中.

I have a PhantomJS/CasperJS script which I'm running from within a node.js script using process.spawn(). Since CasperJS doesn't support require()ing modules, I'm trying to print commands from CasperJS to stdout and then read them in from my node.js script using spawn.stdout.on('data', function(data) {}); in order to do things like add objects to redis/mongoose (convoluted, yes, but seems more straightforward than setting up a web service for this...) The CasperJS script executes a series of commands and creates, say, 20 screenshots which need to be added to my database.

但是，我不知道如何将data变量(Buffer?)分成几行...我尝试将其转换为字符串，然后进行替换，正在执行spawn.stdout.setEncoding('utf8');，但似乎没有任何效果...

However, I can't figure out how to break the data variable (a Buffer?) into lines... I've tried converting it to a string and then doing a replace, I've tried doing spawn.stdout.setEncoding('utf8'); but nothing seems to work...

这就是我现在拥有的

var spawn = require('child_process').spawn;

var bin = "casperjs"
//googlelinks.js is the example given at http://casperjs.org/#quickstart
var args = ['scripts/googlelinks.js'];
var cspr = spawn(bin, args);

//cspr.stdout.setEncoding('utf8');
cspr.stdout.on('data', function (data) {
    var buff = new Buffer(data);
    console.log("foo: " + buff.toString('utf8'));
});

cspr.stderr.on('data', function (data) {
    data += '';
    console.log(data.replace("\n", "\nstderr: "));
});

cspr.on('exit', function (code) {
    console.log('child process exited with code ' + code);
    process.exit(code);
});

https://gist.github.com/2131204

推荐答案

尝试一下:

cspr.stdout.setEncoding('utf8');
cspr.stdout.on('data', function(data) {
  var str = data.toString(), lines = str.split(/(\r?\n)/g);
  for (var i=0; i<lines.length; i++) {
    // Process the line, noting it might be incomplete.
  }
});

请注意，数据"事件不一定在输出的两行之间平均中断，因此一行可能跨越多个数据事件.

Note that the "data" event might not necessarily break evenly between lines of output, so a single line might span multiple data events.

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