Recursive File Search in .net

Question

I need to search a drive (C:, D: etc) for a partuicular file type (extension like .xml, .csv, .xls). How do I preform a recursive search to loop all directories and inner directories and return the full path of where the file(s) are? or where can I get information on this?

VB.NET or C#

Thanks

Edit ~ I am running into some errors like unable to access system volume access denied etc. Does anyone know where I can see some smaple code on implementing a file search? I just need to search a selected drive and return the full path of the file type for all the files found.

score 55 · Answer 1 · answered Jan 13 '09 at 01:54

55

System.IO.Directory.GetFiles(@"c:\", "*.xml", SearchOption.AllDirectories);

answered Jan 13 '09 at 01:54

Cristian Libardo

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score 21 · Accepted Answer · answered Jan 13 '09 at 08:25

How about this? It avoids the exception often thrown by the in-built recursive search (i.e. you get access-denied to a single folder, and your whole search dies), and is lazily evaluated (i.e. it returns results as soon as it finds them, rather than buffering 2000 results). The lazy behaviour lets you build responsive UIs etc, and also works well with LINQ (especially First(), Take(), etc).

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
static class Program { // formatted for vertical space
    static void Main() {
        foreach (string match in Search("c:\\", "*.xml")) {
            Console.WriteLine(match);
        }
    }
    static IEnumerable<string> Search(string root, string searchPattern) {
        Queue<string> dirs = new Queue<string>();
        dirs.Enqueue(root);
        while (dirs.Count > 0) {
            string dir = dirs.Dequeue();

            // files
            string[] paths = null;
            try {
                paths = Directory.GetFiles(dir, searchPattern);
            } catch { } // swallow

            if (paths != null && paths.Length > 0) {
                foreach (string file in paths) {
                    yield return file;
                }
            }

            // sub-directories
            paths = null;
            try {
                paths = Directory.GetDirectories(dir);
            } catch { } // swallow

            if (paths != null && paths.Length > 0) {
                foreach (string subDir in paths) {
                    dirs.Enqueue(subDir);
                }
            }
        }
    }
}

Hmm... just got a downvote out of the blue - care to explain why? — Marc Gravell, Oct 02 '09 at 15:36
Maybe it's the use of 'catch{}'. I don't mean to offend, but that's quite bad practice. Better to catch the AccessDeniedException or DirectoryNotFoudnException, or whatever ... HTH — JamieH, Nov 21 '09 at 05:43

score 5 · Answer 3 · answered Nov 19 '09 at 23:40

It looks like the recls library - stands for recursive ls - now has a pure .NET implementation. I just read about it in Dr Dobb's.

Would be used as:

using Recls;
using System;
static class Program { // formatted for vertical space
    static void Main() {
        foreach(IEntry e in FileSearcher.Search(@"c:\", "*.xml|*.csv|*.xls")) {
            Console.WriteLine(e.Path);
        }
    }

Recursive File Search in .net

3 Answers3

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