/// <summary>
/// Returns offset as -1 if the path is not in Unc format, otherwise returns the root length.
/// </summary>
/// <param name="path"></param>
/// <returns></returns>
internal static int GetUncRootLength(ReadOnlySpan <char> path)
{
bool isDevice = PathInternal.IsDevice(path);
if (!isDevice && StringSpanHelpers.Equals(path.Slice(0, 2), @"\\"))
{
return(2);
}
else if (isDevice && path.Length >= 8 &&
(StringSpanHelpers.Equals(path.Slice(0, 8), PathInternal.UncExtendedPathPrefix) ||
StringSpanHelpers.Equals(path.Slice(5, 4), @"UNC\")))
{
return(8);
}
return(-1);
}
public static string GetFullPath(string path, string basePath)
{
if (path == null)
{
throw new ArgumentNullException(nameof(path));
}
if (basePath == null)
{
throw new ArgumentNullException(nameof(basePath));
}
if (!IsPathFullyQualified(basePath))
{
throw new ArgumentException(SR.Arg_BasePathNotFullyQualified, nameof(basePath));
}
if (basePath.Contains('\0') || path.Contains('\0'))
{
throw new ArgumentException(SR.Argument_InvalidPathChars);
}
if (IsPathFullyQualified(path))
{
return(GetFullPath(path));
}
int length = path.Length;
string combinedPath = null;
if ((length >= 1 && PathInternal.IsDirectorySeparator(path[0])))
{
// Path is current drive rooted i.e. starts with \:
// "\Foo" and "C:\Bar" => "C:\Foo"
// "\Foo" and "\\?\C:\Bar" => "\\?\C:\Foo"
combinedPath = Join(GetPathRoot(basePath.AsSpan()), path);
}
else if (length >= 2 && PathInternal.IsValidDriveChar(path[0]) && path[1] == PathInternal.VolumeSeparatorChar)
{
// Drive relative paths
Debug.Assert(length == 2 || !PathInternal.IsDirectorySeparator(path[2]));
if (StringSpanHelpers.Equals(GetVolumeName(path), GetVolumeName(basePath)))
{
// Matching root
// "C:Foo" and "C:\Bar" => "C:\Bar\Foo"
// "C:Foo" and "\\?\C:\Bar" => "\\?\C:\Bar\Foo"
combinedPath = Join(basePath, path.AsSpan().Slice(2));
}
else
{
// No matching root, root to specified drive
// "D:Foo" and "C:\Bar" => "D:Foo"
// "D:Foo" and "\\?\C:\Bar" => "\\?\D:\Foo"
combinedPath = !PathInternal.IsDevice(basePath)
? path.Insert(2, @"\")
: length == 2
? JoinInternal(basePath.AsSpan().Slice(0, 4), path, @"\")
: JoinInternal(basePath.AsSpan().Slice(0, 4), path.AsSpan().Slice(0, 2), @"\", path.AsSpan().Slice(2));
}
}
else
{
// "Simple" relative path
// "Foo" and "C:\Bar" => "C:\Bar\Foo"
// "Foo" and "\\?\C:\Bar" => "\\?\C:\Bar\Foo"
combinedPath = JoinInternal(basePath, path);
}
// Device paths are normalized by definition, so passing something of this format
// to GetFullPath() won't do anything by design. Additionally, GetFullPathName() in
// Windows doesn't root them properly. As such we need to manually remove segments.
return(PathInternal.IsDevice(combinedPath)
? RemoveRelativeSegments(combinedPath, PathInternal.GetRootLength(combinedPath))
: GetFullPath(combinedPath));
}