// Returns the directory path of a file path. This method effectively
// removes the last element of the given file path, i.e. it returns a
// string consisting of all characters up to but not including the last
// backslash ("\") in the file path. The returned value is null if the file
// path is null or if the file path denotes a root (such as "\", "C:", or
// "\\server\share").
public static string GetDirectoryName(string path)
{
if (string.IsNullOrWhiteSpace(path))
{
if (path == null)
{
return(null);
}
throw new ArgumentException(SR.Arg_PathEmpty, nameof(path));
}
PathInternal.CheckInvalidPathChars(path);
path = PathInternal.NormalizeDirectorySeparators(path);
int root = PathInternal.GetRootLength(path);
int i = path.Length;
if (i > root)
{
while (i > root && !PathInternal.IsDirectorySeparator(path[--i]))
{
;
}
return(path.Substring(0, i));
}
return(null);
}
// Returns the directory path of a file path. This method effectively
// removes the last element of the given file path, i.e. it returns a
// string consisting of all characters up to but not including the last
// backslash ("\") in the file path. The returned value is null if the file
// path is null or if the file path denotes a root (such as "\", "C:", or
// "\\server\share").
public static string GetDirectoryName(string path)
{
if (path != null)
{
PathInternal.CheckInvalidPathChars(path);
path = PathInternal.NormalizeDirectorySeparators(path);
int root = PathInternal.GetRootLength(path);
int i = path.Length;
if (i > root)
{
i = path.Length;
if (i == root)
{
return(null);
}
while (i > root && !PathInternal.IsDirectorySeparator(path[--i]))
{
;
}
return(path.Substring(0, i));
}
}
return(null);
}
// Returns the directory path of a file path. This method effectively
// removes the last element of the given file path, i.e. it returns a
// string consisting of all characters up to but not including the last
// backslash ("\") in the file path. The returned value is null if the file
// path is null or if the file path denotes a root (such as "\", "C:", or
// "\\server\share").
public static string GetDirectoryName(string path)
{
if (path == null)
{
return(null);
}
if (PathInternal.IsEffectivelyEmpty(path))
{
throw new ArgumentException(SR.Arg_PathEmpty, nameof(path));
}
path = PathInternal.NormalizeDirectorySeparators(path);
int root = PathInternal.GetRootLength(path);
int i = path.Length;
if (i > root)
{
while (i > root && !PathInternal.IsDirectorySeparator(path[--i]))
{
;
}
return(path.Substring(0, i));
}
return(null);
}
public static string GetDirectoryName(string path)
{
if (path == null || PathInternal.IsEffectivelyEmpty(path.AsSpan()))
{
return((string)null);
}
int directoryNameOffset = Path.GetDirectoryNameOffset(path.AsSpan());
return(directoryNameOffset < 0 ? (string)null : PathInternal.NormalizeDirectorySeparators(path.Substring(0, directoryNameOffset)));
}
/// <summary>
/// Returns the directory portion of a file path. This method effectively
/// removes the last segment of the given file path, i.e. it returns a
/// string consisting of all characters up to but not including the last
/// backslash ("\") in the file path. The returned value is null if the
/// specified path is null, empty, or a root (such as "\", "C:", or
/// "\\server\share").
/// </summary>
/// <remarks>
/// Directory separators are normalized in the returned string.
/// </remarks>
public static string?GetDirectoryName(string?path)
{
if (path == null || PathInternal.IsEffectivelyEmpty(path.AsSpan()))
{
return(null);
}
int end = GetDirectoryNameOffset(path.AsSpan());
return(end >= 0 ? PathInternal.NormalizeDirectorySeparators(path.Substring(0, end)) : null);
}
// Returns the root portion of the given path. The resulting string
// consists of those rightmost characters of the path that constitute the
// root of the path. Possible patterns for the resulting string are: An
// empty string (a relative path on the current drive), "\" (an absolute
// path on the current drive), "X:" (a relative path on a given drive,
// where X is the drive letter), "X:\" (an absolute path on a given drive),
// and "\\server\share" (a UNC path for a given server and share name).
// The resulting string is null if path is null.
public static string GetPathRoot(string path)
{
if (path == null)
{
return(null);
}
PathInternal.CheckInvalidPathChars(path);
// Need to return the normalized directory separator
path = PathInternal.NormalizeDirectorySeparators(path);
int pathRoot = PathInternal.GetRootLength(path);
return(pathRoot <= 0 ? string.Empty : path.Substring(0, pathRoot));
}
// Returns the root portion of the given path. The resulting string
// consists of those rightmost characters of the path that constitute the
// root of the path. Possible patterns for the resulting string are: An
// empty string (a relative path on the current drive), "\" (an absolute
// path on the current drive), "X:" (a relative path on a given drive,
// where X is the drive letter), "X:\" (an absolute path on a given drive),
// and "\\server\share" (a UNC path for a given server and share name).
// The resulting string is null if path is null. If the path is empty or
// only contains whitespace characters an ArgumentException gets thrown.
public static string GetPathRoot(string path)
{
if (PathInternal.IsEffectivelyEmpty(path))
{
return(null);
}
ReadOnlySpan <char> result = GetPathRoot(path.AsSpan());
if (path.Length == result.Length)
{
return(PathInternal.NormalizeDirectorySeparators(path));
}
return(PathInternal.NormalizeDirectorySeparators(new string(result)));
}
// Returns the directory path of a file path. This method effectively
// removes the last element of the given file path, i.e. it returns a
// string consisting of all characters up to but not including the last
// backslash ("\") in the file path. The returned value is null if the file
// path is null or if the file path denotes a root (such as "\", "C:", or
// "\\server\share").
public static string GetDirectoryName(string path)
{
if (path == null)
{
return(null);
}
if (PathInternal.IsEffectivelyEmpty(path))
{
throw new ArgumentException(SR.Arg_PathEmpty, nameof(path));
}
path = PathInternal.NormalizeDirectorySeparators(path);
int end = PathInternal.GetDirectoryNameOffset(path);
return(end >= 0 ? path.Substring(0, end) : null);
}
// Returns the root portion of the given path. The resulting string
// consists of those rightmost characters of the path that constitute the
// root of the path. Possible patterns for the resulting string are: An
// empty string (a relative path on the current drive), "\" (an absolute
// path on the current drive), "X:" (a relative path on a given drive,
// where X is the drive letter), "X:\" (an absolute path on a given drive),
// and "\\server\share" (a UNC path for a given server and share name).
// The resulting string is null if path is null. If the path is empty or
// only contains whitespace characters an ArgumentException gets thrown.
public static string GetPathRoot(string path)
{
if (path == null)
{
return(null);
}
if (PathInternal.IsEffectivelyEmpty(path))
{
throw new ArgumentException(SR.Arg_PathEmpty, nameof(path));
}
// Need to return the normalized directory separator
path = PathInternal.NormalizeDirectorySeparators(path);
int pathRoot = PathInternal.GetRootLength(path);
return(pathRoot <= 0 ? string.Empty : path.Substring(0, pathRoot));
}
// Returns the root portion of the given path. The resulting string
// consists of those rightmost characters of the path that constitute the
// root of the path. Possible patterns for the resulting string are: An
// empty string (a relative path on the current drive), "\" (an absolute
// path on the current drive), "X:" (a relative path on a given drive,
// where X is the drive letter), "X:\" (an absolute path on a given drive),
// and "\\server\share" (a UNC path for a given server and share name).
// The resulting string is null if path is null. If the path is empty or
// only contains whitespace characters an ArgumentException gets thrown.
public static string GetPathRoot(string path)
{
if (path == null)
{
return(null);
}
if (string.IsNullOrWhiteSpace(path))
{
throw new ArgumentException(SR.Arg_PathEmpty, nameof(path));
}
PathInternal.CheckInvalidPathChars(path);
// Need to return the normalized directory separator
path = PathInternal.NormalizeDirectorySeparators(path);
int pathRoot = PathInternal.GetRootLength(path);
return(pathRoot <= 0 ? string.Empty : path.Substring(0, pathRoot));
}
// Returns the root portion of the given path. The resulting string
// consists of those rightmost characters of the path that constitute the
// root of the path. Possible patterns for the resulting string are: An
// empty string (a relative path on the current drive), "\" (an absolute
// path on the current drive), "X:" (a relative path on a given drive,
// where X is the drive letter), "X:\" (an absolute path on a given drive),
// and "\\server\share" (a UNC path for a given server and share name).
// The resulting string is null if path is null. If the path is empty or
// only contains whitespace characters an ArgumentException gets thrown.
public static string GetPathRoot(string path)
{
if (path == null)
{
return(null);
}
if (PathInternal.IsEffectivelyEmpty(path))
{
throw new ArgumentException(SR.Arg_PathEmpty, nameof(path));
}
ReadOnlySpan <char> result = GetPathRoot(path.AsReadOnlySpan());
if (path.Length == result.Length)
{
return(PathInternal.NormalizeDirectorySeparators(path));
}
return(PathInternal.NormalizeDirectorySeparators(new string(result)));
}
