Sorting the result of Directory.GetFiles in C#

Question

I have this code to list all the files in a directory.

class GetTypesProfiler
{
    static List<Data> Test()
    {
        List<Data> dataList = new List<Data>();
        string folder = @"DIRECTORY";
        Console.Write("------------------------------------------\n");
        var files = Directory.GetFiles(folder, "*.dll");
        Stopwatch sw;
        foreach (var file in files)
        {   
            string fileName = Path.GetFileName(file);
            var fileinfo = new FileInfo(file);
            long fileSize = fileinfo.Length;
            Console.WriteLine("{0}/{1}", fileName, fileSize);
        }
        return dataList;
    }
    static void Main()
    {
         ...
    }
}

I need to print out the file info based on file size or alphabetical order. How can I sort the result from Directory.GetFiles()?

Apps

Add your data to the list, write a LINQ sorting or a custom IComparer... – Fimbria

possible duplicate of #1199506 – Sunken

Answer 1

Very easy with LINQ.

To sort by name,

var sorted = Directory.GetFiles(".").OrderBy(f => f);

To sort by size,

var sorted = Directory.GetFiles(".").OrderBy(f => new FileInfo(f).Length);

Klemperer

do you know how are the files sorted in the first place when you retrieve them with Directory.GetFile() ? – Micaelamicah

@Bosak: Most likely some order that has to do with the specifics of the filesystem, much like dir gives you a consistent but random-looking order. – Klemperer

On my computer, It gives the files and the directories in alphabetical order. I am using Windows 7 – Adest

Can you explain what that lambda is actually doing? It looks to me as if its returning itself, but that makes little sense. – Tonjatonjes

@Tonjatonjes those lambdas simply map each value in the collection to be sorted to an arbitrary sort value -- this allows e.g. to sort integers by their absolute value with i => Math.Abs(i). But there are many cases where we have a collection of comparable values and we just want to sort it without any fancy projections. Sort integers by value? OrderBy(i => i). Sort strings by value? OrderBy(s => s). In this instance we are sorting filenames (strings) exactly like that. – Klemperer

Answer 2

To order by date: (returns an enumerable of FileInfo):

Directory.GetFiles(folder, "*.dll").Select(fn => new FileInfo(fn)).
                                    OrderBy(f => f.Length);

or, to order by name:

Directory.GetFiles(folder, "*.dll").Select(fn => new FileInfo(fn)).
                                    OrderBy(f => f.Name);

Making FileInfo instances isn't necessary for ordering by file name, but if you want to apply different sorting methods on the fly it's better to have your array of FileInfo objects in place and then just OrderBy them by Length or Name property, hence this implementation. Also, it looks like you are going to create FileInfo anyway, so it's better to have a collection of FileInfo objects either case.

Sorry I didn't get it right the first time, should've read the question and the docs more carefully.

Lifeguard

GetFiles returns a string array, not fileinfo. – Coenurus

This doesn't sort by file length, it sorts by filename length. – Klemperer

That will sort on length of filenames, not length of files themselves. – Freak

Answer 3

You can use LINQ if you like, on a FileInfo object:

var orderedFiles =  Directory.GetFiles("").Select(f=> new FileInfo(f)).OrderBy(f=> f.CreationTime)

Coenurus

To get newest files first: var orderedFiles = Directory.GetFiles("").Select(f=> new FileInfo(f)).OrderByDescending(f=> f.CreationTime) – Analemma

Answer 4

try this, it works for me

[System.Runtime.InteropServices.DllImport("Shlwapi.dll", CharSet = System.Runtime.InteropServices.CharSet.Unicode)]
private static extern int StrCmpLogicalW(string psz1, string psz2);
DirectoryInfo di = new DirectoryInfo(path);
FileInfo[] arrFi = di.GetFiles("*.*");
Array.Sort(arrFi, delegate(FileInfo x, FileInfo y) { return StrCmpLogicalW(x.Name, y.Name); });

Deplore

Answer 5

This works if you only need to sort by file name and the file title supports the ascending or descending logical order.I add variables to have a bit more control of the source and search pattern.

Using Dir = System.IO;

string Source = yourVariable;
string SearchPattern = yourVariable;

Dir.Directory.GetFiles(Source, SearchPattern, Dir.SearchOption.AllDirectories).OrderBy(s => s).ToList();

Secrecy

Answer 6

// Getting Directory object
DirectoryInfo directoryInfo = new DirectoryInfo(folderName);

// getting files for this folder
FileInfo[] files = directoryInfo.GetFiles();

// Sorting using the generic Array.Sort function based on Names comparison
Array.Sort(files, delegate (FileInfo x, FileInfo y) { return String.Compare(x.Name, y.Name); });

// Sorting using the generic Array.Sort function based on the creation date of every folder
Array.Sort(files, delegate (FileInfo x, FileInfo y) { return DateTime.Compare(x.CreationTime, y.CreationTime); });

Array Sort

Indocile

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