c# - Given full path, check if path is subdirectory of some other path, or otherwise

Question

I have 2 strings - dir1 and dir2, and I need to check if one is sub-directory for other. I tried to go with Contains method:

dir1.contains(dir2);

but that also returns true, if directories have similar names, for example - c:abc and c:abc1 are not sub-directories, bet returns true. There must be a better way.

Answer 1

DirectoryInfo di1 = new DirectoryInfo(dir1);
DirectoryInfo di2 = new DirectoryInfo(dir2);
bool isParent = di2.Parent.FullName == di1.FullName;

Or in a loop to allow for nested sub-directories, i.e. C:fooaraz is a sub directory of C:foo :

DirectoryInfo di1 = new DirectoryInfo(dir1);
DirectoryInfo di2 = new DirectoryInfo(dir2);
bool isParent = false;
while (di2.Parent != null)
{
    if (di2.Parent.FullName == di1.FullName)
    {
        isParent = true;
        break;
    }
    else di2 = di2.Parent;
}