Comparing characters in strings

[Hidden-Coder]

G'day all,

I'm currently a little stuck with my application. The strings i'm working with are a filepath and then a filename, what I want is to compare the filename with the filepath and then output the directory that most matches with the filename. My current code below works like the following:

Filepath: C:\Program Files\ABCDE Folder\system
Filename: ABCDE.exe
Return: ABCDE Folder

However it wouldn't work if the first few characters don't match, for example:

Filepath: C:\Program Files\ABCDE Folder\system
Filename: ACDE.exe or AAABBBCCDDEE.exe
Return: null

What i'm aiming for is to find out a way to get some sort of percentage of "accuracy" of the filename to any given directory within the filepath. Thanks again for any input. :D

public string FindProgramName(string FullPath)
        {
            string filename;
            string PathuntilFile;

            filename = Path.GetFileNameWithoutExtension(FullPath);
            PathuntilFile = Path.GetDirectoryName(FullPath);

            filename = filename.ToLower();
			string[] pathComponents = PathuntilFile.ToLower().Split(new string[] { @"\" }, StringSplitOptions.RemoveEmptyEntries);
			foreach (string comp in pathComponents)
			{
				int matches = 0;
				for (int i = 0;  i < comp.Length && i < filename.Length; i++)
				{
					if (comp[i] == filename[i])
					{
						if (++matches == 3)
							return comp;
					}
					else
					{
						break;
					}
				}
			}
			return "";
		}

[jonsca]

Sounds like you need regular expressions.
Here's a succinct tutorial I came across. They are toting some product or something but it has a few good examples of what you might need towards the bottom of the page.
http://www.radsoftware.com.au/articles/regexlearnsyntax.aspx

Here's the MSDN page that gives a couple of oversimplified examples but that should give you some of the syntax.
http://msdn.microsoft.com/en-us/library/ms228595(VS.80).aspx

I would imagine there's some linguistics material out there that deals with the kind of statistical processing of which you speak but it might be overkill for this.

[Geekitygeek]

Also, if your going to be trying out regex, i found this online tool to be quite handy. Alternatively, you can download a free version of Expresso...great tool for putting together complex regular expressions, you can break it down into sections etc. Helped me get a handle on them :)

[Hidden-Coder]

Thank guys for all your replies. I'll check it out and see if I can get it to work. I'll keep you updated.