using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(?s)\\begin\{[^{}]*}(?:(?!\\(?:end|begin)).|(?R))*\\end\{[^{}]*}";
string input = @"meh meh
\begin{itemize}
\item something1
\begin{itemize}
\item something1.1
\item something1.2
\end{itemize}
\item something2
\begin{itemize}
\item something2.1
\item something2.2
\end{itemize}
\end{itemize}
blah blah
\begin{itemize}
\item somethingelse1
\item somethingelse2
\end{itemize}
the end.";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
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