More or less obvious is :
\[start\](.*?)\[end\]
but that yields the [start] and [end] tag too. How do you omit them?
E.g.: f("[somestartstring]result[someendstring]") == "result"
UPDATE: the suggested answers are not working. My code is:
printfn "%s" (Regex.Match(@"[start]result[end]",
"\\[start\\](.*?)\\[end\\]").Groups.[0].Value)
but it still yields the surrounding start and end tags.
My mistake is: the 0 index! Thank you.
You need to use a group, which is a match string within parantheses:
\[start\](.*?)\[end\]
These are numbered from 1 when you come to read them (zero being the whole matched string). (There is also the facility of named groups if you find that more intuitive.)
E.g. in C#:
Match match = new Regex("\[start\](.*?)\[end\]").Match("[start]blah[end]");
string value = match.Groups[1].Value;
Remember Groups[0] matches the entire input. If you just want the first captured group it is Groups[1], so
string text = "[start]blahblah[end]";
Console.WriteLine(Regex.Match(text, @"\[start\](.*?)\[end\]").Groups[1].Value);
prints blahblah.
Use \[start\](.*?)\[end\]
C#
Regex regex = new Regex("\\[start\\](.*?)\\[end\\]");
VB
Dim regex As Regex = New Regex("\[start\](.*?)\[end\]")
Depends on the language. Usually you have to specify the matching group you want returned; often group zero is the whole matching expression, 1 is the first matching group, 2 is the second matching group, and so forth.
Update 1: please see http://www.regular-expressions.info/dotnet.html
Update 2: Author seemed to think he understood .NET syntax. So removing code example and letting answer stand on its own.
[start]whatever[end], and manually remove the first 7 and the last 5 characters, leavingwhatever.