What is an easy way to check if directory 1 is a subdirectory of directory 2 and vice versa?
I checked the Path and DirectoryInfo helperclasses but found no system-ready function for this. I thought it would be in there somewhere.
Do you guys have an idea where to find this?
I tried writing a check myself, but it's more complicated than I had anticipated when I started.
public static bool IsSubfolder(DirectoryInfo parentPath, DirectoryInfo childPath)
{
return parentPath.FullName.StartsWith(childPath.FullName+Path.DirectorySeparatorChar);
}
With help from the great test cases written in angularsen's answer, I wrote the following simpler extension method on .NET Core 3.1 for Windows:
public static bool IsSubPathOf(this string dirPath, string baseDirPath, StringComparison comparisonType = StringComparison.OrdinalIgnoreCase)
{
dirPath = dirPath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
if (!dirPath.EndsWith(Path.DirectorySeparatorChar))
{
dirPath += Path.DirectorySeparatorChar;
}
baseDirPath = baseDirPath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
if (!baseDirPath.EndsWith(Path.DirectorySeparatorChar))
{
baseDirPath += Path.DirectorySeparatorChar;
}
string dirPathUri = new Uri(dirPath).LocalPath;
string baseDirUri = new Uri(baseDirPath).LocalPath;
return dirPathUri.Contains(baseDirUri, comparisonType);
}