Read the last line of a CSV file and extract one value

New to Node.js and trying to pull a value from the very last line of a CSV file. Here is the CSV:

Unit ID,Date,Time,Audio File
Log File Created,3/6/2013,11:18:25 AM,file:\C:UsersBenDocuments1_03-06-2013_1114-50.mp3
1,3/6/2013,11:20:24 AM,file:\C:AlertLog1_03-06-2013_1120-24.mp3
1,3/6/2013,11:20:39 AM,file:\C:AlertLog1_03-06-2013_1120-24.mp3

The part I am trying to grab is file:\C:AlertLog1_03-06-2013_1120-24.mp3 – preferably getting rid of the file:\ part.

Sorry that I do not have any code to show, just have a few hours of experience with Node.js and cannot seem to find any docs on how to accomplish something like this. Any help would be appreciated. Thanks!

Regular file

Read the file like a regular file, split the file contents into lines, take the last line, split by a comma and take the last part.

var fs = require('fs'); // file system module

fs.readFile('/path/to/file.csv', 'utf-8', function(err, data) {
    if (err) throw err;

    var lines = data.trim().split('n');
    var lastLine = lines.slice(-1)[0];

    var fields = lastLine.split(',');
    var audioFile = fields.slice(-1)[0].replace('file:\\', '');

    console.log(audioFile);
});

File System module documentation

CSV parser

You can also use the node-csv-parser module.

var fs = require('fs');
var csv = require('csv');

csv()
 .from.stream(fs.createReadStream('/path/to/file.csv'))
 .to.array(function(data, count) {
    var lastLine = data.slice(-1)[0];
    var audioFile = lastLine.slice(-1)[0].replace('file:\\', '');
    console.log(audioFile);
  });

I did it in by reading the file backwards until last line was read:

var fs = require('fs');
var path = require('path');
var fileName = path.join(__dirname, 'test.txt');
var readLastLine = function(name, callback) {
    fs.stat(name, function(err, stat) {
        fs.open(name, 'r', function(err, fd) {
            if(err) throw err;
            var i = 0;
            var line = '';
            var readPrevious = function(buf) {
                fs.read(fd, buf, 0, buf.length, stat.size-buf.length-i, function(err, bytesRead, buffer) {
                    if(err) throw err;
                    line = String.fromCharCode(buffer[0]) + line;
                    if (buffer[0] === 0x0a) { //0x0a == 'n'
                        callback(line);
                    } else {
                        i++;
                        readPrevious(new Buffer(1));
                    }
                });
            }
            readPrevious(new Buffer(1));
        });
    });
}
readLastLine(fileName, function(line) {
    console.log(line);
});