如何将 process.stdin 的输入与 NodeJS 中的字符串进行比较? [英] How to compare input from process.stdin to string in NodeJS?

问题描述

我正在使用 nodeJS，并且我希望能够通过 stdin 向它传递命令.为此，我使用 process.stdin.理想情况下，我有一个带有各种命令字符串的巨大开关，例如加载"或停止"，但我无法进行比较.我试过切出换行符，转换为字符串等.无法弄清楚这一点，虽然它看起来应该相当简单.

I'm using nodeJS and I want to be able to pass it commands via stdin. To do this I'm using process.stdin. Ideally I'd have a giant switch with various command strings like "load" or "stop", but I can't get the comparison to work. I've tried slicing out newlines, converting to strings, etc. Can't figure this out, though it seems like it should be fairly simple.

以下是我一直在努力工作的代码:

Below is the code I've been trying to get to work:

process.stdin.setEncoding('utf8');

process.stdin.on('readable', function() {
  var chunk = process.stdin.read();

  if(chunk === null)
    return;

  //i've tried this as well, to no avail
  //chunk = chunk.toString();

  if(chunk == "expectedinput")
    console.log("got it!");

  process.stdout.write('data: ' + chunk);

});

推荐答案

通常，如果您想从 stdin 读取换行符分隔的输入，最容易使用内置的 readline 模块.

Typically if you want to read newline-delimited input from stdin, it's easiest to use the built-in readline module.

但是，对于您的原始代码，问题很可能在于输入的分块和/或换行符也被捕获，因此您最终必须将其剥离或将条件更改为类似 if(chunk == "expectedinput\n")(假设您已经缓冲了足够的输入数据以查看换行符).

However for your original code, the problem most likely is either in the chunking of the input and/or that the newline is also captured, so you'd eventually have to either strip it off or change your conditional to something like if(chunk == "expectedinput\n") (assuming you have buffered enough input data to see the newline).

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