Question

I am trying to retrieve list of files from a server with the windows command – “DIR /S/B”
The output is huge (around 400 MB). Now when I tried retrieve it with below approach, its taking hours to process. Is there any faster way to do it.

string path = args[0];
var start = DateTime.Now;

System.Diagnostics.ProcessStartInfo procStartInfo =
    new System.Diagnostics.ProcessStartInfo("cmd", "/c " + "dir /s/b " + path );
procStartInfo.RedirectStandardOutput = true;
procStartInfo.UseShellExecute = false;
procStartInfo.CreateNoWindow = true;
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo = procStartInfo;
proc.Start();

//string [] result = proc.StandardOutput.ReadToEnd().Split('\n'); ;

StreamWriter writer = new StreamWriter("FileList.lst");
while (proc.StandardOutput.EndOfStream != true)
{
    writer.WriteLine(proc.StandardOutput.ReadLine());
    writer.Flush();
}
writer.Close();

Answer 1

Why not use DirectoryInfo.GetFiles?

I’m guessing quite a bit of your time now is being eaten up by the command executing, not the .NET code. It’ll take dir a long time to write that much data to a stream in sequence. You then use String.Split which is also going to choke on that much data.

By using DirectoryInfo.GetFiles, you should be able to get all the file names in a single line (and you could also get other information about the files this way):

var files = (new DirectoryInfo(path)
                .GetFiles("*.*", SearchOption.AllDirectories)
                .Select(fi => fi.Name);

If you’re really only concerned about filenames, you could use:

var fileNames = Directory.GetFiles(path, "*.*", SearchOption.AllDirectories);