Match text separated by SINGLE forward slash only

Question

I am trying to split strings similar to this using Regex.Split:

https://www.linkedin.com/in/someone

To return this:

Effectively, ignoring double forward slash and only worrying about a single forward slash.

I know I should be using something like this /(?!/) negative look ahead - but can't get it to work.

This is not a duplicate of this Similar Question, because if you run that regular expression through Regex.Split, it does not give the required result.

This could be helpful: https://stackoverflow.com/questions/161738/what-is-the-best-regular-expression-to-check-if-a-string-is-a-valid-url — Praveen, May 21 '18 at 06:54
@Praveen, while I appreciate your answer - perhaps you should read my question again. — c0D3l0g1c, May 21 '18 at 07:00
Possible duplicate of [Split string on single forward slashes with RegExp](https://stackoverflow.com/questions/32586057/split-string-on-single-forward-slashes-with-regexp) — l'L'l, May 21 '18 at 07:12
There is a solution at the above duplicate that produces the exact desired result using the following pattern (`[^/]+(?://[^/]*)*`)... — l'L'l, May 21 '18 at 07:13
Why not use the [Uri](https://msdn.microsoft.com/en-us/library/system.uri(v=vs.110).aspx) class instead? `Uri.Segments` will return all segments of the path. `Host` will return `www.linkedin.com`. It won't be affected by query parameters and fragments like a regex either. `new Uri(@"https://www.linkedin.com/in/someone?someparam=foo#tab1").Segments` will return `\ `, `in`, `someone` — Panagiotis Kanavos, May 21 '18 at 07:42

score 6 · Accepted Answer · edited May 21 '18 at 07:19

6

How about this: (?<!/)/(?!/)

Breaking it down:

(?<!/): negative lookbehind for / characters
/: match a single / character
(?!/): negative lookahead for / characters

Taken together, we match a / character that does not have a / both before and after it.

Example usage:

string text = "https://www.linkedin.com/in/someone";
string[] tokens = Regex.Split(text, "(?<!/)/(?!/)");
foreach (var token in tokens)
{
    Console.WriteLine($"Token: {token}");
}

Output:

Token: https://www.linkedin.com
Token: in
Token: someone

edited May 21 '18 at 07:19

41686d6564

15,043
11
32
63

answered May 21 '18 at 07:12

Samantha

915
6
20

Your solution is better than mine. I have no idea why I didn't use `Regex.Split()`. +1 for simplicity. – 41686d6564 May 21 '18 at 07:19
Exactly what I needed! – c0D3l0g1c May 21 '18 at 09:01

leofun01 · Answer 2 · 2018-05-21T07:41:16.373

0

Also you can do it using this code :

string pattern = @"([^\/]+(\/{2,}[^\/]+)?)";
string input = @"https://www.linkedin.com/in/someone";
foreach(Match match in Regex.Matches(input, pattern)) {
    Console.WriteLine(match);
}

Output :

https://www.linkedin.com
in
someone

edited May 21 '18 at 07:41

answered May 21 '18 at 07:30

leofun01

126
1
8

score 0 · Answer 3 · answered May 21 '18 at 08:21

As mentioned by @Panagiotis Kanavos in the comments section above, why make things complicated when you can use the Uri Class:

Provides an object representation of a uniform resource identifier (URI) and easy access to the parts of the URI.

public static void Main()
{
    Uri myUri = new Uri("https://www.linkedin.com/in/someone");   
    string host =  myUri.Scheme + Uri.SchemeDelimiter  + myUri.Host;
    Console.WriteLine(host);        
}

OUTPUT:

DEMO:

dotNetFiddle

Match text separated by SINGLE forward slash only

3 Answers3