Listing of files using C#

I recently downloaded the Visual Studio 2008 for C#. I like the ease of program development. I started off with Console Applications to learn C#. In C/C++ you can get a listing of all the files of a certain type by using the following command:

Code:

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system("dir/s /b *.txt >text.dat");

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I could not find a similar command in C#, so I wrote a recursive function to traverse all the subdirectories of a particular directory and write a list of the files into a text file that match the file extension passed into the function. The FileStream is passed into the function after being created in the 'Main' part of the program and closed there after the function returns. The function works fine as intended, but my question is this, "Is there a less cumbersome method in C# to use which will accomplish what the above mentioned system command in 'C' does?

Code:

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        static void WriteDirInformation(string FullDirPath, FileStream fs, string File_ext)
        {
            System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(@FullDirPath);
            string fullPath = Path.GetFullPath(@FullDirPath);
            fullPath += "\\";

            Console.WriteLine("Files in {0}", FullDirPath);
            foreach (System.IO.FileInfo file in dir.GetFiles(File_ext))
            {
                string fullFilePath = fullPath + file.Name;
                Console.WriteLine("{0}", fullFilePath);
                fullFilePath += "\n";
                byte[] info = new UTF8Encoding(true).GetBytes(fullFilePath);
                fs.Write(info, 0, info.Length);
            }
            DirectoryInfo[] diArr = dir.GetDirectories();

            // Display the names of the directories.
            if (diArr.Length > 0)
            {
                foreach (DirectoryInfo dri in diArr)
                {
                    string fullDirPath = fullPath + dri.Name;
                    Console.WriteLine(fullDirPath);
                    WriteDirInformation(fullDirPath, fs, File_ext);
                }
            }
        }

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Code:

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                public static void Main(string[] args)
                {
                        List<FileInfo> files = new List<FileInfo>();
                        GetAllFile(@"C:\MyFiles", "*.txt",  files);
                        using (StreamWriter w = new StreamWriter(@"contents.txt"))
                                files.ForEach(delegate (FileInfo f) { w.WriteLine(f.Name); });
                }
               
                public static GetAllFiles(string path, string filter, List<FileInfo> files)
                {

                        foreach (string dir in Directory.GetDirectories(path))
                                GetAllFiles (Path.Combine(path, dir));
                       
                        foreach (string file in Directory.GetFiles(path, filter))
                                files.Add(new FileInfo(Path.Combine(path, file)));
                }
        }

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Is that any easier for ya?

In case you just want to take it to single line then you can use Process Class's Start method like this

Code:

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            System.Diagnostics.Process.Start(@"C:\Windows\system32\cmd.exe",@"/c dir /s/b C:\MyFolders > C:\files.dat");

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Thanks Shuja Ali and Mutant_Fruit for your replies. I especially like the one-line command rather then writing a lot of code. I tried your code, Shuja Ali, and it works (just changed the target directory from C:\MyFolders to one of my existing directories).
Mutant_Fruit, I liked your solution, also, but it contained typos and only wrote the filenames without the path to the files to "contents.txt". I fixed the typos and changed the target directory and now your solution works as I intended. Here is the

Code:

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      public static void Main(string[] args)
                {
                        List<FileInfo> files = new List<FileInfo>();
                        GetAllFiles(@"C:\tmp1\", "*.txt",  files);
                        using (StreamWriter w = new StreamWriter(@"contents.txt"))
                                files.ForEach(delegate (FileInfo f)
                                {
                                            w.WriteLine(f.DirectoryName + "\\" + f.Name);
                                }
                            );
                }
               
                public static void GetAllFiles(string path, string filter, List<FileInfo> files)
                {

                        foreach (string dir in Directory.GetDirectories(path))
                GetAllFiles(Path.Combine(path, dir), filter, files);
                       
                        foreach (string file in Directory.GetFiles(path, filter))
                                files.Add(new FileInfo(Path.Combine(path, file)));
                }

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Aye, i never compiled it, the idea should be clear though ;)

The benefit of doing it entirely with .NET code is that you can process the list of files after you generate em. You can sort them, modify them, remove duplicates, whatever. You lose that ability by calling the command prompt. Also, calling the command prompt isn't portable ;) If you want to run your app on different operating systems, then you can't do it that way.

Glad ya got it working anyway.