using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"\[{2}([\w\s()]+)(?:\|([\w\s]+))?\]{2}";
string input = @"""[[December 1]] A triangular [[Conjunction (astronomy)|conjunction]] formed by a new Moon, Venus and Jupiter is a [[Conjunction (astronomy)#2008|prominent sight]] in the evening sky. [[December 2]]""
";
foreach (Match m in Regex.Matches(input, pattern))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx