Removing or Trimming \ (back slash)

Question

I need some help please!

 

I am writing an ASP.Net web app and I am trying to get the Current User Identity and then bounce that off a database to see if the user is authorized to use the app.

 

I get the identity fine (by using CurrentIdentity.Name) but I get back the computer name and the user name like “computername\username”.

 

How can I remove or trim off the “computername\” to get just the user name?

 

I have seen a lot of examples for getting the file name and trimming with Char [] but when I use the \ I get errors when I build.

 

Thanks for any and all help!

Kurt

Answer 1

The String class has numerous methods that you might find useful.  If you know the computername ahead of time, then you know how many characters are on the front of the string.

 

Code Block

void MethodA()

{

string user = "computername";

user = user.Remove(IntStartIndex, IntCharCount);

}

 

 

IntStartIndex would be here.....at the red slash...well just past it.

Code Block

computername\username

 

 

 

 

IntCharCount is how many characters to the end of the string.  That would be the difference between the overall length of "user" and the length of the computername on the front.  Hope this helps.

 

Rudedog

Answer 2

Backslashes begin escape sequences. You might want to escape the backslash with another backslash, e.g.:

string a = "\\"; -> \

Hope this helps.

Answer 3

What about:

String userName = userName.Substring(userName.IndexOf('\') + 1);

Answer 4

How about Path.GetFileName()?

Answer 5

Thanks to everyone who has replied, I appreciate the help!

 

So far I have not had any luck with the suggestions.

 

Matt, on the Path.GetFileName option I only have PathDirection available. Am I missing a using statement or something?

 

I am thinking I need to parse this data out and then select what I need. Does that make sense to anyone? If so then I would need to figure that out, it is just a thought I had.

 

Sorry I am relatively new to programming.

 

Thanks,

Kurt

 

Answer 6

try

stringObject.Substring(stringObject.IndexOf("\\")+1)

 

Also read about Substring @ http://msdn2.microsoft.com/en-us/library/hxthx5h6.aspx

 

Cheers

Answer 7

C# DevMan wrote:

Matt, on the Path.GetFileName option I only have PathDirection available. Am I missing a using statement or something?

I think the full thing is System.IO.Path.GetFileName()

Answer 8

Like Matt said

 

System.IO.Path.GetFileName(@"computername\username")

 

works.

 

I'm pretty suprised as I neved tought of using this function for something else than a filename. Clever

Answer 9

System.IO.Path.GetFileName is a terrible idea. It uses the System.IO.Path.DirectorySeparatorChar as the separator char, and this is NOT guaranteed to be \ - for example on Japanese systems it is the Yen symbol, and if the application were to run on Mono then it would be a / on Unix/Linux. Don't use functions for things they aren't designed for, especially if you don't understand the limitations.

A safe way to do it, which would handle the possibility that the name is returned without the domain, which is possible for built-in accounts, would be:

int separatorIndex = myUsernameString.LastIndexOf(@"\");
if (separatorIndex != -1 && separatorIndex < myUsernameString.Length - 1)
{
    myUsernameString = myUsernameString.Substring(separatorIndex + 1);
}

Answer 10

Greg is right, forget what I just said.

Answer 11

Thanks again everyone for the suggestions!!

 

Greg,

I am trying to implement your suggestion but I am getting errors when I build. FYI: This will be running on a local Intranet only.

 

Can you help me with the code?

 

Here is the code I have which is working to grab the Current Identity and display the results on a label "computername\username".

 

using System.Security.Principal;

public partial class TrimTest : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

//grab the current user

WindowsIdentity currentIdentity = WindowsIdentity.GetCurrent();

//assigning the ID to the label to show results

LblUserID.Text = currentIdentity.Name;

 

}

}

 

Thanks,

Kurt

Answer 12

Greg Beech wrote:

System.IO.Path.GetFileName is a terrible idea. It uses the System.IO.Path.DirectorySeparatorChar as the separator char, and this is NOT guaranteed to be \ - for example on Japanese systems it is the Yen symbol, and if the application were to run on Mono then it would be a / on Unix/Linux.

This is true - but I was answering according to the title of this thread, which is "Removing or Trimming \ (back slash) From File Path"

Answer 13

Ah good point - I hadn't spotted that the title didn't match the question!

In which case you're quite right, for file paths what you suggested is exactly the way to do it.

Answer 14

I'm confused am I missing something?

 

Did I not post the title and the question correctly?

 

I believe what was returned by the get current identity and that which I am trying to trim is a file path, correct?

 

Kurt

Answer 15

C# DevMan wrote:

I'm confused am I missing something?   Did I not post the title and the question correctly?   I believe what was returned by the get current identity and that which I am trying to trim is a file path, correct?   Kurt

 

Have you found a workable solution?  Food for thought.  It's easy to enumerate Arrays and ArrayList types.

 

Code Block

public static string MyConvert(string s)

{

byte[] MyString = Convert.FromBase64String(s);

string output = Convert.ToBase64String(MyString);

return output;

}