This very problem is commonly referred to in IT Security parlance as a
"Canonicalization" problem. The problem arises from the fact that the
path to a file or directory can be represented in a large number of
ways and if your validations are limited to string comparison, you are
almost certainly bound to fail when validating malicious input. For
instance, the path to the Program files directory can be expressed
(atleast) as "c:\program files" and "c;\progra~1".
The best practice to avoid this problem is usually to allow the OS to
canonicalize the absolute path to the file or directory before
applying any validation of your own. In your case, you should use the
System.IO.Path.GetFullPath() method to obtain a path string that will
be the same (except for case) irrespective of the input you receive in
your textbox. For example :
---
using System.IO;
..
..
string p1 = Path.GetFullPath(txtPath1.Text);
string p2 = Path.GetFullPath(txtPath2.Text);
if(string.Equals(p1, p2, StringComparison.OrdinalIgnoreCase))
MessageBox.Show("Same");
else
MessageBox.Show("Different");
---
On Dec 21, 12:56 pm, Aidan Whitehall <[email protected]>
wrote:
> A C# WinForm application has two text boxes, each of which allows the
> user to specify a directory. Both directories must differ.
>
> How can you detect when user has put in txtA "C:\temp" and "C:\temp\"
> in txtB?
>
> Directory.Exists() on both returns true and comparison of txtA.Text
> and txtB.Text says they differ.
>
> I really don't want to get into string manipulation if at all possible
> (have got in a mess in the past treating date/times as strings) and
> have looked through the Directory, DirectoryInfo and Path classes to
> see if there is any way of doing something along the lines of:
>
> Compare( Directory.GetReference( txtA ), Directory.GetReference
> ( txtB ) )
>
> Thanks for any pointers.
>
> Aidan
