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C# regex need characters after \player_n\

Answer 1

+3 A:

Try this one:

\\player_\d+\\([^\\]+)

elusive 2010-09-09 18:32:02

+1 -- Hint: for regular expressions, it's best to post the pure expression without language specific additions. Like in this case, the regex literal notation `/slashes/` are not meaningful in C#.

Tomalak 2010-09-09 18:44:09

Thanks for your addition! I used them in Perl for my entire life, so delimiters seem quite natural to me.

elusive 2010-09-09 18:45:50

it didnt work, but if i remove the "/" from each end, i get a match "\player_n\playername\" .. which is ok, but i would prefer just "playername" by itself

brux 2010-09-09 18:46:39

You need to use the first match group. I do not know how this works in C#, but this is not too difficult in any other language that knows about regular expressions.

elusive 2010-09-09 18:47:55

@brux: See http://www.regular-expressions.info/dotnet.html to get a quick overview (how to handle groups is explained there as well).

Tomalak 2010-09-09 18:52:18

var match = Regex.Match(stringData, @"\\player_\d+\\([^\\]+)");textBox1.Text += match.Captures[0].ToString();textBox1.Text += match.Captures[1].ToString(); it crashes when adding the second match to the textbox. if i remove this instruction then the first match (0) gets added fine.

brux 2010-09-09 19:12:55

its as though its oly finding 1 match, but there are plenty of player names in the string :s

brux 2010-09-09 19:16:01

Answer 2

+1 A:

To get only the player name, you could use:

(?<=\\player_\d+\\)[^\\]+

This (?<=\\player_\d+\\) is something called a positive look-behind. It makes sure that the actual match [^\\]+ is preceded by the expression in the parentheses.

In this case, it's even specific to only a few regex engines (.NET being among them, luckily), in that it contains a variable length expression (due to \d+). Most regex engines only support fixed-length look-behind.

In any case, look-behind is not necessarily the best approach to this problem, match groups are simpler easier to read.

Tomalak 2010-09-09 18:51:08

hi tomolak, im going with the regex posted by elusive since it works ok. but if i try and add the second match to the textbox i get an "out of range error". if i remove that line the first match (0) is added ok. in the string i compare to the pattern, there are about 8 playernames :s

brux 2010-09-09 19:15:13

@brux: If you get "out of range" errors you are doing it wrong anyway. Always do range checks in your code.

Tomalak 2010-09-09 19:32:46

Answer 3

+1 A:

i think that this test sample can help you

string inp = @"\g79g97\g879o\wot87gord\player_0\name0\g6868o\g78og89\g79g79\player_1\name1\gyuvui\yivyil\player_2\name2\g7g87\g67og9o\v78v9i7";
string rex = @"[\w]*[\\]player_[0-9]+[\\](?<name>[A-Za-z0-9]*)\b";
Regex re = new Regex(rex);
Match mat = re.Match(inp);
 for (Match m = re.Match(inp); m.Success; m = m.NextMatch())
{
     Console.WriteLine(m.Groups["name"]);
}

you can take the name of the player from the m.Groups["name"]

Ghiath Zarzar 2010-09-09 19:35:05

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C# regex need characters after \player_n\

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