C# Search for subdirectory (not for files)

Question

Every example I see seems to be for recursively getting files in subdirectories uses files only. What I'm trying to do is search a folder for a particular subdirectory named "xxx" then save that path to a variable so I can use it for other things.

Is this possible without looping through all the directories and comparing by name?

Answer 1

Well

Directory.GetDirectories(root);

will return you an array of the subdirectories.

You can then use Linq to find the one you're interested in:

IEnumerable<string> list = Directory.GetDirectories(root).Where(s => s.Equals("test"));

which isn't a loop in your code, but is still a loop nevertheless. So the ultimate answer is that "no you can't find a folder 'test' without looping".

You could add .SingleOrDefault() to the Linq, but that would depend on what you wanted to do if your "test" folder couldn't be found.

If you change the GetDirectories call to include the SearchOption SearchOption.AllDirectories then it will do the recursion for you as well. This version supports searching - you have to supply a search string - though in .NET Framework it's case sensitive searching. To return all sub directories you pass "*" as the search term.

Obviously in this case the call could return more than one item if there was more than one folder named "test" in your directory tree.

Answer 2

var foldersFound = Directory.GetDirectories(root, "test", SearchOption.AllDirectories)

This will return a string array with all the folders found with the given name. You can change the last parameter so that it only checks top level directories and you can change root to adjust where it is starting from.

Answer 3

First of all, "No, it is not possible without looping through all the directories and comparing by name".

I believe your real question is "Is there an existing API which will handle looping through all the directories and comparing by name for me?"

Yes, there is. It's called Directory.Exists() :

var xxxPath = Path.Combine(parentFolder, "xxx");
if (Directory.Exists(xxxPath))
    savedPath = xxxPath;

Answer 4

是的，我相信唯一可用的解决方案（缺少第三方库）是通过名称比较递归搜索目录。

Answer 5

You can use Windows Search which provides api for .Net too. Here is more detailed information: Windows Search 4.0 for Developers

Answer 6

Here is a snippet for searching for a folder using two filters while considering for the UnauthorizedAccessException, it can be refactored to use only one filter:

public static string FindGitPath(string firstFilter, string secondFilter, string initialPath)
    {
        string gitPath = string.Empty;
        foreach (var i in Directory.GetDirectories(initialPath)) {          
            try {
                foreach (var f in Directory.GetDirectories(i, firstFilter, SearchOption.AllDirectories)) {
                    foreach (var s in Directory.GetDirectories(f)) {
                        if (s == Path.Combine(f,secondFilter)) {
                            gitPath = f;
                            break;
                        }
                    }
                }       
            } catch (UnauthorizedAccessException) {
                Console.WriteLine("Path is not accessible: {0}", i);
            }                               
        }
        return gitPath; 
    }

Usage example:

Console.WriteLine("Retrieved the git database folder as {0}", FindGitPath("database",".git", "c:\\"));