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flexd/cardreader.js

Created November 29, 2012 17:46
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Revisions

  1. flexd created this gist Nov 29, 2012.
    54 changes: 54 additions & 0 deletions cardreader.js
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,54 @@
    var spawn = require('child_process').spawn;
    var util = require('util');
    var EventEmitter = require('events').EventEmitter;

    function CardReader() {

    var reader;

    var lastUID = "";
    var me = this;
    function spawnReader() {
    reader = spawn('python', ['uidgrabber.py']);
    console.log("uidgrabber running pid: " + reader.pid);
    }

    function handleExit(reader) {
    reader.on('exit', function (code) {
    console.log('uidgrabber process exited with code ' + code);
    me.emit('exit', code);
    spawnReader();
    handleExit(reader);
    });
    }
    spawnReader();
    handleExit(reader);

    // Handle stuff.

    reader.stderr.on('data', function (data) {
    console.log('stderr: ' + data);
    me.emit('error', data);
    });

    reader.stdout.on('data', function (data) {

    var data = data.toString();
    data = data.replace(/\u001b\[\d{0,2}m/g, ''); // Remove ANSI colors.
    var uid = /UID: (.+)/.exec(data);

    if (uid) {
    uid = uid[1];
    if (uid != lastUID) {
    // This is not the last card we read, so lets emit it.
    me.emit('cardRead', uid);
    }
    lastUID = uid;
    }
    });
    }

    util.inherits(CardReader, EventEmitter);
    exports.createReader = function () {
    return new CardReader();
    }