For every letter in a string, print its ascii character representation

Question

I am reading from a socket and trying to debug some of the messages which are coming in. Right now, I am trying to see if there is any "invisible" letters sneaking past my regex. I do the following in order to get the literal string values.

socket.on('data', function (data) {
  const message = data.toString('ascii');
  let characters = [];
  message.forEach((letter, i) => characters.push(message.charCodeAt(i)));
  console.log(characters);
});

The result looks like this:

[58, 13, 10, 26]

I want to get something more human readable without a (manual) look up of each letter on an ascii table. That is, the list would look more like this:

[':', '\r', '\n', 'ctrl-z']
// or
[':', 'carriage return', 'new line', 'substitution']

Is there any way of accomplishing this with Node.js?

Answer 1

In node 5.1, you can just split the string into an array of characters and console.log the array. The built in console.log will print escape codes for non printing characters:

socket.on('data', function(data){
    const message = data.toString('ascii');
    console.log(message.split(''))
})

If you are using a lower version of node, you can use the util package in node to get a string literal representation of your character.

Something like this should work:

socket.on('data', function(data){
    const message = data.toString('ascii');
    console.log(message.split('').map(function(c){
        return require('util').inspect(c);
    }))
})

Answer 2

使用message.charAt(i)代替charCodeAt 。