如何在Node.js中无限读取

Question

while(1){
    rl.question("Command: ",function(answer){
    console.log(answer);
    })
}

刚刚尝试了这段代码，但是逐个输入，它会使“Command：”行闪烁。我知道node.js是非阻塞的，但我不知道如何解决这个问题。

Answer 1

var readline = require('readline');
var log = console.log;

var rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

var recursiveAsyncReadLine = function () {
  rl.question('Command: ', function (answer) {
    if (answer == 'exit') //we need some base case, for recursion
      return rl.close(); //closing RL and returning from function.
    log('Got it! Your answer was: "', answer, '"');
    recursiveAsyncReadLine(); //Calling this function again to ask new question
  });
};

recursiveAsyncReadLine(); //we have to actually start our recursion somehow

关键是不要使用同步循环。我们应该在处理答案后才问下一个rl.question。递归是要走的路。我们定义函数，询问问题并处理答案，然后在答案处理后从内部调用它。这样我们就开始了，就像常规循环一样。但循环不关心ansyc代码，而我们的实现关心。

Answer 2

通过Node.js文档的另一个选择是使用events：

var readline = require('readline'),
    rl = readline.createInterface(process.stdin, process.stdout);

rl.setPrompt('OHAI> ');
rl.prompt();

rl.on('line', function(line) {
    switch(line.trim()) {
        case 'hello':
            console.log('world!');
            break;
        default:
            console.log('Say what? I might have heard `' + line.trim() + '`');
        break;
    }
    rl.prompt();
}).on('close', function() {
    console.log('Have a great day!');
    process.exit(0);
});