using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(?:(?:[\s\w]*(?:({(?:[\s\w]*%\(\w*\)[\s\w]*)+(?:{(?:[\s\w]*%\(\w*\)[\s\w]*)+})*})+)[\s\w]*)+)$";
string input = @"# Your valid example
abc {st1 %(ph1) st11} int {st2 %(ph2) st22}{st3 %(ph3) st33 {st31 %(ph4) st332}} cd
# Your valid Legenda
OptionalStaticText{OptionalStaticText %(Placeholder) OptionalStaticText {OptionalSubSection} OptionalStaticText} OptionalStaticText
# Your invalid example
abc {st1 %(ph1) st11} int {st2 %(ph2) st22}{st3 %(ph3) st33 {st31 %(ph4) st332}} c-d
# Without pre / post optional static text and some optional text inside section
{%(Placeholder) OptionalStaticText {OptionalSubSection}}
# With only a placeholder in the section
OptionalStaticText{%(Placeholder)} OptionalStaticText
# The valid version
abc {st1 %(ph1) st11} int {st2 %(ph2) st22}{st3 %(ph3) st33 {st31 %(ph4) st332}} cd
";
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