public static bool IsPathRooted(ReadOnlySpan <char> path)
{
int length = path.Length;
return((length >= 1 && PathInternal.IsDirectorySeparator(path[0])) ||
(length >= 2 && PathInternal.IsValidDriveChar(path[0]) && path[1] == PathInternal.VolumeSeparatorChar));
}
public static bool IsPathRooted(string path)
{
// Want to avoid PathInternal.CheckInvalidPathChars on Path.IsPathRooted
if (path != null)
{
int length = path.Length;
if ((length >= 1 && PathInternal.IsDirectorySeparator(path[0])) ||
(length >= 2 && PathInternal.IsValidDriveChar(path[0]) && path[1] == Path.VolumeSeparatorChar))
{
return(true);
}
}
return(false);
}
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));
}
if (PathInternal.IsEffectivelyEmpty(path.AsSpan()))
{
return(basePath);
}
int length = path.Length;
string combinedPath;
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.AsSpan(1)); // Cut the separator to ensure we don't end up with two separators when joining with the root.
}
else if (length >= 2 && PathInternal.IsValidDriveChar(path[0]) && path[1] == PathInternal.VolumeSeparatorChar)
{
// Drive relative paths
Debug.Assert(length == 2 || !PathInternal.IsDirectorySeparator(path[2]));
if (GetVolumeName(path.AsSpan()).EqualsOrdinal(GetVolumeName(basePath.AsSpan())))
{
// Matching root
// "C:Foo" and "C:\Bar" => "C:\Bar\Foo"
// "C:Foo" and "\\?\C:\Bar" => "\\?\C:\Bar\Foo"
combinedPath = Join(basePath.AsSpan(), path.AsSpan(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.AsSpan())
? path.Insert(2, @"\")
: length == 2
? JoinInternal(basePath.AsSpan(0, 4), path.AsSpan(), @"\".AsSpan())
: JoinInternal(basePath.AsSpan(0, 4), path.AsSpan(0, 2), @"\".AsSpan(), path.AsSpan(2));
}
}
else
{
// "Simple" relative path
// "Foo" and "C:\Bar" => "C:\Bar\Foo"
// "Foo" and "\\?\C:\Bar" => "\\?\C:\Bar\Foo"
combinedPath = JoinInternal(basePath.AsSpan(), path.AsSpan());
}
// Device paths are normalized by definition, so passing something of this format (i.e. \\?\C:\.\tmp, \\.\C:\foo)
// to Windows APIs won't do anything by design. Additionally, GetFullPathName() in Windows doesn't root
// them properly. As such we need to manually remove segments and not use GetFullPath().
return(PathInternal.IsDevice(combinedPath.AsSpan())
? PathInternal.RemoveRelativeSegments(combinedPath, PathInternal.GetRootLength(combinedPath.AsSpan()))
: GetFullPath(combinedPath));
}