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C# regex to parse /simple1/1.2-SNAPSHOT/

I need to find the last two values at the end of such a string, "simple1" and "1.2-SNAPSHOT" in the sample url below. But my code below (try to get simple1/1.2-SNAPSHOT/) doesn't work, can anyone help?
http://localhost:8060/nexus/service/local/repositories/snapshots/content/org/sonatype/mavenbook/simple1/1.2-SNAPSHOT/
List<string> artifacts = new List<string>(); // this is already foler URL
// store all URLs to the artifacts be deleted
artifacts = nexusAPI.findArtifacts(repository, contents, days, pattern);
var regex = new Regex(".*\\/(.*\\/.*\\/)$");
foreach (string url in artifacts)
{
Console.WriteLine("group/artifact: {0}", regex.Matches(url));
}

I would just split the string on '/' and get the last two parts. The regex isn't going to do anything more then that.

If you must use RegEx, you're encountering an issue in that regexes are greedy - that means it puts as much in each .* as it possibly can. So your first step is to make the regex not greedy. Simply use this as your pattern:
(.*?)/
Here's a simple test showing how that this works.
This tells the regex to look for any character up to the slash, and then stop.
When you call Regex.Matches(url, "(.*?)/"), you will get returned an array of the matching data. From there, you can just look at the last two elements.
Of course, as SledgeHammer mentioned, this is one case where regex is unnecessary and even cumbersome. Simply working with url.Split(new char[] {'/'}) will give you the results you need.

Need To Fail A Match If It Is Successful

I have this pattern in C#:
string WWPNMatchString = #"port-wwn\s+\(vendor\)\s+:(?<wwpn>..:..:..:..:..:..:..:..)";
I have file with these two lines that occur in pairs several times in the file:
port-wwn (vendor) :50:01:73:80:12:60:01:41
permanent-port-wwn (vendor) :50:01:73:80:12:60:01:41
I only want to match the first line. There are other lines that screw up the data I am parsing where the second line looks like this:
permanent-port-wwn (vendor) :00:00:00:00:00:00:00:00
So, I don't want to match the line that includes permanent. I could do a separate if to check the incoming string but that is messy. the online site I use to check my regular expressions fails the second line, but C# doesn't after the code is compiled.

It occurred to me that the pattern that I don't want always starts with 00:
so I changed the regex to:
string WWPNMatchString = #"port-wwn\s+\(vendor\)\s+:(?<wwpn>[1-9].:..:..:..:..:..:..:..)";
this will exclude anything where the wwpn group starts with 0 - the value I am after, valid values never start with 0.

I assume you're reading the file line by line, and each line is processed as a separate string?
You can force the match to begin at the start of the string by using ^, like this:
#"^port-wwn\s+\(ven...
This will exclude the lines starting with "permanent-".

A regex
string WWPNMatchString = #"^port-wwn\s+\(vendor\)\s+:(?<wwpn>..:..:..:..:..:..:..:..)";

Regular expression for recognizing url

I want to create a Regex for url in order to get all links from input string.
The Regex should recognize the following formats of the url address:
http(s)://www.webpage.com
http(s)://webpage.com
www.webpage.com
and also the more complicated urls like:
- http://www.google.pl/#sclient=psy&hl=pl&site=&source=hp&q=regex+url&pbx=1&oq=regex+url&aq=f&aqi=g1&aql=&gs_sm=e&gs_upl=1582l3020l0l3199l9l6l0l0l0l0l255l1104l0.2.3l5l0&bav=on.2,or.r_gc.r_pw.&fp=30a1604d4180f481&biw=1680&bih=935
I have the following one
((www\.|https?|ftp|gopher|telnet|file|notes|ms-help):((//)|(\\\\))+[\w\d:##%/;$()~_?\+-=\\\.&]*)
but it does not recognize the following pattern: www.webpage.com. Can someone please help me to create an appropriate Regex?
EDIT:
It should works to find an appropriate link and moreover place a link in an appropriate index like this:
private readonly Regex RE_URL = new Regex(#"((https?|ftp|gopher|telnet|file|notes|ms-help):((//)|(\\\\))+[\w\d:##%/;$()~_?\+-=\\\.&]*)", RegexOptions.Multiline);
foreach (Match match in (RE_URL.Matches(new_text)))
{
// Copy raw string from the last position up to the match
if (match.Index != last_pos)
{
var raw_text = new_text.Substring(last_pos, match.Index - last_pos);
text_block.Inlines.Add(new Run(raw_text));
}
// Create a hyperlink for the match
var link = new Hyperlink(new Run(match.Value))
{
NavigateUri = new Uri(match.Value)
};
link.Click += OnUrlClick;
text_block.Inlines.Add(link);
// Update the last matched position
last_pos = match.Index + match.Length;
}

I don't know why your result in match is only http:// but I cleaned your regex a bit
((?:(?:https?|ftp|gopher|telnet|file|notes|ms-help):(?://|\\\\)(?:www\.)?|www\.)[\w\d:##%/;$()~_?\+,\-=\\.&]+)
(?:) are non capturing groups, that means there is only one capturing group left and this contains the complete matched string.
(?:(?:https?|ftp|gopher|telnet|file|notes|ms-help):(?://|\\\\)(?:www\.)?|www\.) The link has now to start with something fom the first list followed by an optional www. or with an www.
[\w\d:##%/;$()~_?\+,\-=\\.&] I added a comma to the list (otherwise your long example does not match) escaped the - (you were creating a character range) and unescaped the . (not needed in a character class.
See this here on Regexr, a useful tool to test regexes.
But URL matching is not a simple task, please see this question here

I've just written up a blog post on recognising URLs in most used formats such as:
www.google.com
http://www.google.com
mailto:somebody#google.com
somebody#google.com
www.url-with-querystring.com/?url=has-querystring
The regular expression used is /((([A-Za-z]{3,9}:(?:\/\/)?)(?:[-;:&=\+\$,\w]+#)?[A-Za-z0-9.-]+|(?:www.|[-;:&=\+\$,\w]+#)[A-Za-z0-9.-]+)((?:\/[\+~%\/.\w-_]*)?\??(?:[-\+=&;%#.\w_]*)#?(?:[\w]*))?)/ however I would recommend you got to http://blog.mattheworiordan.com/post/13174566389/url-regular-expression-for-links-with-or-without-the to see a complete working example along with an explanation of the regular expression in case you need to extend or tweak it.

The regex you give doesn't work for www. addresses because it is expecting a URI scheme (the bit before the URL, like http://). The 'www.' part in your regular expression doesn't work because it would only match www.:// (which is meaningless)
Try something like this instead:
(((https?|ftp|gopher|telnet|file|notes|ms-help):((//)|(\\\\))+)|(www\.)[\w\d:##%/;$()~_?\+-=\\\.&]*)
This will match something with a valid URI scheme, or something beginning with 'www.'

Regex for a string

It would be great if someone could provide me the Regular expression for the following string.
Sample 1: <div>abc</div><br>
Sample 2: <div>abc</div></div></div></div></div><br>
As you can see in the samples provided above, I need to match the string no matter how many number of </div> occurs. If there occurs any other string between </div> and <br>, say like this <div>abc</div></div></div>DEF</div></div><br> OR <div>abc</div></div></div></div></div>DEF<br>, then the Regex should not match.
Thanks in advance.

Try this:
<div>([^<]+)(?:<\/div>)*<br>
As seen on rubular
Notes:
This only works if there are not tags in the abc part (or anything that has a < symbol).
You might want to use start and end of string anchors (^<div>([^<]+)(?:<\/div>)*<br>$ if you want your string to match the pattern exactly.
If you want to allow the abc part to be empty, use * instead of +
That being said, you should be wary of using regex to parse HTML.
In this example, you can use regex because you are parsing a (hopefully) known, regular subset of HTML. But a more robust solution (ie: an [X]HTML parser like HtmlAgilityPack) is preferred when it comes to parsing HTML.

You need to use a real parser. Things like infinitely nested tags can't be handled via regex.

You could also include a named group in the the expression, e.g.:
<div>(?<text>[^<]*)(?:<\/div>)*<br>
Implemented in C#:
var regex = new Regex(#"<div>(?<text>[^<]*)(?:<\/div>)*<br>");
Func<Match, string> getGroupText = m => (m.Success && m.Groups["text"] != null) ? m.Groups["text"].Value : null;
Func<string, string> getText = s => getGroupText(regex.Match(s));
Console.WriteLine(getText("<div>abc</div><br>"));
Console.WriteLine(getText("<div>123</div></div></div></div></div><br>"));

NullUserException's answer is good. Here are a couple of questions, and variations, depending on what you want.
Do you want to prevent anything from occurring before the open div tag? If so, keep the ^ at the beginning of the regex. If not, drop it.
The rest of this post refers to the following section of the regex:
([^<]+?)
Do you want to capture the contents of the div, or just know that it matches your form? To capture, leave it as is. If you don't need to capture, drop the parentheses from the above.
Do you want to match if there is nothing inside the div? If so change the + in the above to *
Finally, although it will work fine, you don't need the ? in the above.

I think, this regex is more flexible:
<div\b[^><]*+>(?>.*?</div>)(?:\s*+</div>)*+\s*+<br(?:\s*+/)?>
I don't include the ^ and $ in the beginning and the end of my regex because we cannot assure that your sample will always in a single line.

Regex BBCode to HTML

I writing BBcode converter to html.
Converter should skip unclosed tags.
I thought about 2 options to do it:
1) match all tags in once using one regex call, like:
Regex re2 = new Regex(#"\[(\ /?(?:b|i|u|quote|strike))\]");
MatchCollection mc = re2.Matches(sourcestring);
and then, loop over MatchCollection using 2 pointers to find start and open tags and than replacing with right html tag.
2) call regex multiple time for every tag and replace directly:
Regex re = new Regex(#"\[b\](.*?)\[\/b\]");
string s1 = re.Replace(sourcestring2,"<b>$1</b>");
What is more efficient?
The first option uses one regex but will require me to loop through all tags and find all pairs, and skip tags that don't have a pair.
Another positive thins is that I don't care about the content between the tags, i just work and replace them using the position.
In second option I don't need to worry about looping and making special replace function.
But will require to execute multiple regex and replaces.
What can you suggest?
If the second option is the right one,
there is a problem with regex
\[b\](.*?)\[\/b\]
how can i fix it to also match multi lines like:
[b]
test 1
[/b]
[b]
test 2
[/b]

One option would be to use more SAX-like parsing, where instead of looking for a particular regex you look for [, then have your program handle that even in some manner, look for the ], handle that even, etc. Although more verbose than the regex it may be easier to understand, and wouldn't necessarily be slower.

r = new System.Text.RegularExpressions.Regex(#"(?:\[b\])(?<name>(?>\[b\](?<DEPTH>)|\[/b\](?<-DEPTH>)|.)+)(?(DEPTH)(?!))(?:\[/b\])", System.Text.RegularExpressions.RegexOptions.Singleline);
var s = r.Replace("asdfasdf[b]test[/b]asdfsadf", "<b>$1</b>");
That should give you only elements that have matched closing tags and also handle multi line (even though i specified the option of SingleLine it actually treats it as a single line)
It should also handle [b][b][/b] properly by ignoring the first [b].
As to whether or not this method is better than your first method I couldn't say. But hopefully this will point you in the right direction.
Code that works with your example below:
System.Text.RegularExpressions.Regex r;
r = new System.Text.RegularExpressions.Regex(#"(?:\[b\])(?<name>(?>\[b\](?<DEPTH>)|\[/b\](?<-DEPTH>)|.)+)(?(DEPTH)(?!))(?:\[/b\])", System.Text.RegularExpressions.RegexOptions.Singleline);
var s = r.Replace("[b]bla bla[/b]bla bla[b] " + "\r\n" + "bla bla [/b]", "<b>$1</b>");