public unsafe static string GetCaseSensitivePath(string path)
{
using SafeFileHandle hFile = PInvoke.CreateFile(
lpFileName: path,
dwDesiredAccess: (FILE_ACCESS_FLAGS) 0,
dwShareMode: FILE_SHARE_FLAGS.FILE_SHARE_READ | FILE_SHARE_FLAGS.FILE_SHARE_WRITE | FILE_SHARE_FLAGS.FILE_SHARE_DELETE,
lpSecurityAttributes: null,
dwCreationDisposition: FILE_CREATE_FLAGS.OPEN_EXISTING,
dwFlagsAndAttributes: FILE_FLAGS_AND_ATTRIBUTES.FILE_FLAG_BACKUP_SEMANTICS,
hTemplateFile: null);
if (hFile.IsInvalid)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
Span <char> name = stackalloc char[1024];
uint size = PInvoke.GetFinalPathNameByHandle(
hFile: hFile,
lpszFilePath: (char *)Unsafe.AsPointer(ref name[0]),
cchFilePath: (uint)name.Length,
dwFlags: FILE_NAME.FILE_NAME_NORMALIZED);
if (size == 0 || size > name.Length)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
if (name.StartsWith(@"\\?\"))
{
name = name.Slice(4);
}
return(MemoryMarshal.CreateReadOnlySpanFromNullTerminated((char *)Unsafe.AsPointer(ref name[0])).ToString());
}
public static unsafe IDictionary GetEnvironmentVariables()
{
// Format for GetEnvironmentStrings is:
// [=HiddenVar=value\0]* [Variable=value\0]* \0
// See the description of Environment Blocks in MSDN's CreateProcess
// page (null-terminated array of null-terminated strings). Note
// the =HiddenVar's aren't always at the beginning.
// Copy strings out, parsing into pairs and inserting into the table.
// The first few environment variable entries start with an '='.
// The current working directory of every drive (except for those drives
// you haven't cd'ed into in your DOS window) are stored in the
// environment block (as =C:=pwd) and the program's exit code is
// as well (=ExitCode=00000000).
char *stringPtr = Interop.Kernel32.GetEnvironmentStringsW();
if (stringPtr == null)
{
throw new OutOfMemoryException();
}
try
{
var results = new Hashtable();
char *currentPtr = stringPtr;
while (true)
{
ReadOnlySpan <char> variable = MemoryMarshal.CreateReadOnlySpanFromNullTerminated(currentPtr);
if (variable.IsEmpty)
{
break;
}
// Find the = separating the key and value. We skip entries that begin with =. We also skip entries that don't
// have =, which can happen on some older OSes when the environment block gets corrupted.
int i = variable.IndexOf('=');
if (i > 0)
{
// Add the key and value.
string key = new string(variable.Slice(0, i));
string value = new string(variable.Slice(i + 1));
try
{
// Add may throw if the environment block was corrupted leading to duplicate entries.
// We allow such throws and eat them (rather than proactively checking for duplication)
// to provide a non-fatal notification about the corruption.
results.Add(key, value);
}
catch (ArgumentException) { }
}
// Move to the end of this variable, after its terminator.
currentPtr += variable.Length + 1;
}
return(results);
}
finally
{
Interop.BOOL success = Interop.Kernel32.FreeEnvironmentStringsW(stringPtr);
Debug.Assert(success != Interop.BOOL.FALSE);
}
}
public static unsafe void CreateReadOnlySpanFromNullTerminated_Char_Null()
{
Assert.True(MemoryMarshal.CreateReadOnlySpanFromNullTerminated((char *)null).IsEmpty);
Assert.True(MemoryMarshal.CreateReadOnlySpanFromNullTerminated((byte *)null).IsEmpty);
}
internal static nuint wcslen([NativeTypeName("wchar_t const*")] ushort * @_String)
{
return((uint)MemoryMarshal.CreateReadOnlySpanFromNullTerminated((char *)@_String).Length);
}
