Pausing readline in Node.js

Question

Consider the code below ... I am trying to pause the stream after reading the first 5 lines:

var fs          = require(\'fs\');
var readline    = require(\'r         


        

Answer 1

add some points:

.on('pause', function() {
    console.log(numlines)
})

You will get the 5. It mentioned in the node.js document :

• The input stream is not paused and receives the SIGCONT event. (See events SIGTSTP and SIGCONT)

So, I created a tmp buffer in the line event. Use a flag to determine whether it is triggered paused.

.on('line', function(line) {
   if (paused) {
      putLineInBulkTmp(line);
   } else {
      putLineInBulk(line);
   }
}

then in the on pause, and resume:

.on('pause', function() {
    paused = true;
    doSomething(bulk, function(resp) {
        // clean up bulk for the next.
        bulk = [];
        // clone tmp buffer.
        bulk = clone(bulktmp);
        bulktmp = [];
        lr.resume();
    });
})
.on('resume', () => {
  paused = false;
})

Use this way to handle this kind of situation.