public static IEnumerable <FileInfo> GetFiles(DirectoryInfo startDirectory, string pattern, bool recurse)
{
// We suppressed this demand for each p/invoke call, so demand it upfront once
new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Demand();
// Validate parameters
Verify.IsNotNull(startDirectory, "startDirectory");
Verify.IsNeitherNullNorEmpty(pattern, "pattern");
// Setup
var findData = new WIN32_FIND_DATAW();
var directories = new Stack <DirectoryInfo>();
directories.Push(startDirectory);
// Process each directory. Only push new directories if we're recursing.
ErrorModes origErrorMode = NativeMethods.SetErrorMode(ErrorModes.FailCriticalErrors);
try
{
while (directories.Count > 0)
{
// Get the name of the next directory and the corresponding search pattern
DirectoryInfo dir = directories.Pop();
string dirPath = dir.FullName.Trim();
if (dirPath.Length == 0)
{
continue;
}
char lastChar = dirPath[dirPath.Length - 1];
if (lastChar != Path.DirectorySeparatorChar && lastChar != Path.AltDirectorySeparatorChar)
{
dirPath += Path.DirectorySeparatorChar;
}
// Process all files in that directory
using (SafeFindHandle handle = NativeMethods.FindFirstFileW(dirPath + pattern, findData))
{
Win32Error error;
if (handle.IsInvalid)
{
error = Win32Error.GetLastError();
if (error == Win32Error.ERROR_ACCESS_DENIED || error == Win32Error.ERROR_FILE_NOT_FOUND)
{
continue;
}
Assert.AreNotEqual(Win32Error.ERROR_SUCCESS, error);
((HRESULT)error).ThrowIfFailed();
}
do
{
if (!Utility.IsFlagSet((int)findData.dwFileAttributes, (int)FileAttributes.Directory))
{
yield return(new FileInfo(dirPath + findData.cFileName));
}
}while (NativeMethods.FindNextFileW(handle, findData));
error = Win32Error.GetLastError();
if (error != Win32Error.ERROR_NO_MORE_FILES)
{
((HRESULT)error).ThrowIfFailed();
}
}
// Push subdirectories onto the stack if we are recursing.
if (recurse)
{
// In a volatile system we can't count on all the file information staying valid.
// Catch reasonable exceptions and move on.
try
{
foreach (DirectoryInfo childDir in dir.GetDirectories())
{
try
{
FileAttributes attrib = File.GetAttributes(childDir.FullName);
// If it's not a hidden, system folder, nor a reparse point
if (!Utility.IsFlagSet((int)attrib, (int)(FileAttributes.Hidden | FileAttributes.System | FileAttributes.ReparsePoint)))
{
directories.Push(childDir);
}
}
catch (FileNotFoundException)
{
// Shouldn't see this.
Assert.Fail();
}
catch (DirectoryNotFoundException) { }
}
}
catch (DirectoryNotFoundException) { }
}
}
}
finally
{
NativeMethods.SetErrorMode(origErrorMode);
}
}
/// <summary>
/// Convert the result of Win32 GetLastError() into a raised exception.
/// </summary>
public static void ThrowLastError()
{
((HRESULT)Win32Error.GetLastError()).ThrowIfFailed();
// Only expecting to call this when we're expecting a failed GetLastError()
Assert.Fail();
}