Fastest way to remove `..` and related folder from path?

Question

The question

Given a path like thus:

G:\path\foo\..\bar\baz.txt

Which we can immediately parse in our minds, and as the OS will parse as:

G:\path\bar\baz.txt

What's the fastest way to do that programmatically? In other words, does a library function already exist that will do this for me cleanly so that I don't botch it myself.

My first shot at an answer

// in pseudocode
string[] s = input.split('\')
string output
for ( int i = s.length ; i > 0 ; i-- ) {
  if ( s[i] == ".." ) i--;
  else output = s[i] + "\" + output
}
return output

But notice that this answer doesn't cover the case (unexpected, but potential) for

G:\path\foo\..\..\bar\baz.txt

which would of course be

G:\bar\baz.txt

TSQL functions will work as well!!!!!

---

Not important to the question but I felt like sharing ;)

I'm passing it from a returned value (off a webservice call) into a sproc (for XML shredding) and want to eliminate the foo\..\ as the value I pass in is used as the key for preventing duplicate processing later. If I insert G:\path\foo\..\bar\baz.txt and another script inserts G:\path\bar\baz.txt the file will be processed twice.

Answer 1

Try

System.IO.Path.GetFullPath(@"G:\path\foo\..\..\bar\baz.txt");

Answer 2

public static string System.IO.Path.GetFullPath(string path) 

is what you need.