I am trying to make a File Directory browser in C# for a project.
I start with the current path (for this example it will be '/').
From the list of paths that I have
Example: /a/b, /a/bb, /a/bbb, /b/a, /b/aa, /b/aaa, /c/d, /d/e
I would like to return a list of distinct subdirectories
Expected return: /a/, /b/, /c/, /d/
How would one go about using LINQ to accomplish this?
I think this just about covers it. Sample console app:
public static void Main()
{
string[] paths = new[] { "/a/b", "/a/bb", "/a/bbb", "/b/a", "/b/aa", "/b/aaa", "/c/d", "/d/e" };
string root = "/";
Console.WriteLine(string.Join(", ", paths.Select(s => GetSubdirectory(root, s)).Where(s => s != null).Distinct()));
}
static string GetSubdirectory(string root, string path)
{
string subDirectory = null;
int index = path.IndexOf(root);
Console.WriteLine(index);
if (root != path && index == 0)
{
subDirectory = path.Substring(root.Length, path.Length - root.Length).Trim('/').Split('/')[0];
}
return subDirectory;
}
See fiddle: http://dotnetfiddle.net/SXAqxY
Sample input: "/"
Sample output: a, b, c, d
Sample input: "/a"
Sample output: b, bb, bbb
I may missing the point, but wouldn't something like this be what you are looking for?
var startingPath = @"c:\";
var directoryInfo = new DirectoryInfo(startingPath);
var result = directoryInfo.GetDirectories().Select(x => x.FullName).ToArray();
The result would be an array of paths to the various immediate sub directories (example):
Assuming you have a list of paths named paths
, you can do something like this:
string currentDirectory = "/";
var distinctDirectories = paths.Where(p => p.StartsWith(currentDirectory)
.Select(p => GetFirstSubDir(p, currentDirectory)).Distinct();
...
string GetFirstSubDir(string path, string currentDirectory)
{
int index = path.IndexOf('/', currentDirectory.Length);
if (index >= 0)
return path.SubString(currentDirectory.Length - 1, index + 1 - currentDirectory.Length);
return path.SubString(currentDirectory.Length - 1);
}
You can use Path.GetPathRoot
var rootList = new List <string>();
foreach (var fullPath in myPaths)
{
rootList.Add(Path.GetPathRoot(fullPath))
}
return rootList.Distinct();
Or:
myPaths.Select(x => Path.GetPathRoot(x)).Distinct();
Or use Directory.GetDirectoryRoot:
myPaths.Select(x => Directory.GetDirectoryRoot(x)).Distinct();
Edit
If you want the N+1 path you could do:
string dir = @"C:\Level1\Level2;
string root = Path.GetPathRoot(dir);
string pathWithoutRoot = dir.Substring(root.Length);
string firstDir = pathWithoutRoot.Split(Path.DirectorySeparatorChar).First();
void Main()
{
string [] paths = { @"/a/b", @"/a/bb", @"/a/bbb", @"/b/a", @"/b/aa", @"/b/aaa", @"/c/d", @"/d/e" };
var result = paths.Select(x => x.Split('/')[1]).Distinct();
result.Dump();
}
If you don't know if you have a leading /
then use this:
var result = paths.Select(x =>x.Split(new string [] {"/"},
StringSplitOptions.RemoveEmptyEntries)[0])
.Distinct();
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