How to pull the server name from a UNC

Question

Would anyone be able to tell me how to pull the server name out of a UNC?

ex.

//servername/directory/directory

Edit : I apologize but it looks like I need to clarify a mistake: the path actually is more like:

//servername/d$/directory

I know this might change things a little

aren't UNC paths contain backslash characters insted of forward slahes? — SztupY, Jun 27 '09 at 19:31
yeah thats really funny.. nobody caught that (including me!) — KevinDeus, Jun 29 '09 at 22:57
@SztupY They are just as valid as forward slashes. I know that is the case now, but not sure if this was also the case in 2009. — jhyry-gcpud, Jul 01 '21 at 00:58

score 24 · Accepted Answer · answered Jun 27 '09 at 19:21

24

How about Uri:

Uri uri = new Uri(@"\\servername\d$\directory");
string[] segs = uri.Segments;
string s = "http://" + uri.Host + "/" + 
    string.Join("/", segs, 2, segs.Length - 2) + "/";

answered Jun 27 '09 at 19:21

Marc Gravell

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Peter Boughton · Answer 2 · 2009-06-27T17:55:21.830

7

Just another option, for the sake of showing different options:

(?<=^//)[^/]++

The server name will be in \0 or $0 or simply the result of the function, depending on how you call it and what your language offers.

Explanation in regex comment mode:

(?x)      # flag to enable regex comments
(?<=      # begin positive lookbehind
^         # start of line
//        # literal forwardslashes (may need escaping as \/\/ in some languages)
)         # end positive lookbehind
[^/]++    # match any non-/ and keep matching possessively until a / or end of string found.
          # not sure .NET supports the possessive quantifier (++) - a greedy (+) is good enough here.

edited Jun 27 '09 at 17:55

answered Jun 27 '09 at 17:47

Peter Boughton

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I tried this one in C# and got the following error message: parsing "(?<=^//)[^/]++" - Nested quantifier +. – KevinDeus Jun 27 '09 at 18:20
2

@Kevin: just drop the second + symbol. – mechanical_meat Jun 27 '09 at 18:53

score 3 · Answer 3 · answered Jun 27 '09 at 17:14

3

This should do the trick.

^//([^/]+).*

The server name is in the first capturing group

answered Jun 27 '09 at 17:14

jitter

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At the start of a line (^), match two forward slashes (//), then one or more (+) characters that's not another forward slash ([^/]) followed by one or more occurrences of anything (.*) The parens "(" and ")" indicate a 'capturing group'. – mechanical_meat Jun 27 '09 at 17:26
@Adam: Thanks for explaining how the regular expression actually works. – Jason Down Jun 27 '09 at 18:04
1

@Jason: happy to do so. A mistake in my explanation: the * symbol is not 'one or more', it is 'zero or more'. The + symbol is 'one or more' – mechanical_meat Jun 27 '09 at 18:14
using comment 1 here I get the following in c#: //servername/ is there a way to strip off the slashes? (my program) Regex r = new Regex(@"^//(?\w+)/", RegexOptions.IgnoreCase); Match m = r.Match(@"//servername/directory/directory"); CaptureCollection cc = m.Captures; foreach (Capture c in cc) { System.Console.WriteLine(c); } – KevinDeus Jun 27 '09 at 18:18

score 1 · Answer 4 · answered Jun 27 '09 at 17:17

1

Regular expression to match servername:

^//(\w+)

answered Jun 27 '09 at 17:17

Alan Haggai Alavi

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I'm a fan of named capture groups, so I'd probably modify this to: ^//(?\w+)/ – Lee Jun 27 '09 at 17:19
2

\w will match [A-Za-z0-9_] - but server names can contain many more characters than those? – Peter Boughton Jun 27 '09 at 18:03

score 0 · Answer 5 · answered Oct 06 '16 at 15:24

0

Ugly but it just works:

var host = uncPath.Split(new [] {'\\'}, StringSplitOptions.RemoveEmptyEntries).FirstOrDefault();

answered Oct 06 '16 at 15:24

smiron

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score 0 · Answer 6 · answered Jun 15 '23 at 09:43

0

Use System.Uri Host property: https://learn.microsoft.com/en-us/dotnet/api/system.uri.host?view=net-7.0

var path = @"\\servername\d$\directory";
var uncPath = new Uri(path);
var serverName = uncPath.Host; // returns "servername"

answered Jun 15 '23 at 09:43

Andrew Roberts

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How to pull the server name from a UNC

6 Answers6

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