A Directory Size Utility

• Download dirsize.zip - 2.3 KB
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Introduction

This is a little command line utility that will tell you the total size of all files in a directory. It traverses all sub-directories recursively and adds the size of all files - including hidden and system files - in them. Any inaccessible files and directories are ignored.

You can do the same thing with a Windows PowerShell command or with a for loop in a batch script, but this method seemed easier and more customizable to me.

Requirements

This is written using Visual Studio 2013 Express, on .NET Framework 4. Earlier versions of the framework did not support a feature that I will mention later.

Getting the files

We use the DirectoryInfo class to recursively enumerate files in sub-directories.

DirectoryInfo di = new DirectoryInfo(directory);
IEnumerable<FileInfo> files = di.EnumerateFiles("*", SearchOption.AllDirectories);

Note that SearchOption.AllDirectories requests files in all subdirectories recursively. Once you do this, it is a simple matter of traversing the list using its enumerator.

UInt64 size = 0;
IEnumerator<FileInfo> e = files.GetEnumerator();
while (e.MoveNext)
  {  
    size += (UInt64)e.Current;
  }
Console.WriteLine(size);

The Catch

The code above is file if all files are accessible. That is, if the current user has read access rights to all files in the sub-directories. However, if not, e.MoveNext throws an UnauthorizedAccesssException. To get past this problem, we surround e.MoveNext with a try/catch block and ignore any UnauthorizedAccessExceptions.

The modified code is given below.

while (true)
{
    try
    {
       if (!e.MoveNext())
       {
          break;
       }
    }
    catch (UnauthorizedAccessException)
    {
      {
        continue; // ignore exception   
      }
    }
    FileInfo fi = e.Current;
    size += (UInt64)fi.Length;
}

Older .NET versions

Previous versions of DirectoryInfo do not have an EnuerateFiles method, instead it has GetFiles which returns an array of FileInfo. Unlike EnuerateFiles, this immediately throws a security exception if any sub-directory or file is inaccessible, which means we'd have to manually enumerate each file in the current directory, then recursively get sub-directories and files in them. I haven't tried this yet, maybe I'll get around to it some time in a future post.

Conclusion

I haven't tested this much, it'll probably crash under circumstances I didn't foresee. Please leave a comment in that case. Alternative methods are also welcome.