Why doesn't this node script filter the

Question

I'm writing a node script that is supposed to take a directory and an extension name as args, and log all of the files in that directory that end with that extension. Sounds simple enough, but my script returns an empty array:

var fs = require('fs');
var ref = process.argv[2];
var extension = process.argv[3];
var files = [];
var dir = fs.readdir(ref, function(err, list){
    if (err) throw err;    
    var filterRx = new RegExp("\." + extension + "$");
    files = list.filter(function(val){
        return filterRx.test(val);
    });


});
console.log(files);

Can anyone help me understand why this isn't working as expected?

Edit: For example, Given a directory with the following files (given by console.log(list) in the callback):

   "[ 'CHANGELOG.md',"                 !=    "LICENCE.md"                       
   "  'LICENCE.md',"                   !=    "README.md"                        
   "  'README.md',"                    !=    ""                                 
   "  'dat',"                          !=                                       
   "  'data.dat',"                     !=                                       
   "  'data.json',"                    !=                                       
   "  'learnyounode.dat',"             !=                                       
   "  'learnyounode.sql',"             !=                                       
   "  'learnyounode.txt',"             !=                                       
   "  'md',"                           !=                                       
   "  'w00t.dat',"                     !=                                       
   "  'w00t.txt',"                     !=                                       
   "  'words.dat',"                    !=                                       
   "  'wrrrrongdat' ]"

And passing the second argument "md", I should get "CHANGELOG.md", "LICENSE.md", etc

I only get [] :/

Maybe you should check if your regex works properly, could you edit your question and maybe add an example of extension and file name so we can help you further ? — Nicolas, Feb 24 '17 at 13:47
@JoeClay there is nothing about asynchronous call here ? can you please justify your comment — Nicolas, Feb 24 '17 at 13:48
@Nicolas: `fs.readdir` is asynchronous (as are most things by default in Node, hence all the callbacks). If you want to read a directory synchronously, you need to use `fs.readdirSync`. — Joe Clay, Feb 24 '17 at 13:48
@Nicolas: No problem, it's not hugely obvious at first glance! — Joe Clay, Feb 24 '17 at 13:50

Why doesn't this node script filter the

0 Answers0