using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(?m)^```\h*(\S+)";
string substitution = @"<!-- language: lang-\1 -->\n";
string input = @"Do not change this line
```markdown
Sasha great!
Sasha nice!
She is beautiful, surprise!
Do not change this line
Do not change this line
```markdown
Sasha great!
Sasha nice!
She is beautiful, surprise!
Do not change this line
Do not change this line
```markdown
Sasha great!
Sasha nice!
She is beautiful, surprise!
Do not change this line
Do not change this line
```markdown
Sasha great!
Sasha nice!
She is beautiful, surprise!
Do not change this line";
Regex regex = new Regex(pattern);
string result = regex.Replace(input, substitution);
}
}
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