C# Regex Split - commas outside quotes

You could split on all commas, that do have an even number of quotes following them , using the following Regex to find them:

",(?=(?:[^']*'[^']*')*[^']*$)"

You'd use it like

var result = Regex.Split(samplestring, ",(?=(?:[^']*'[^']*')*[^']*$)");

//this regular expression splits string on the separator character NOT inside double quotes. 
//separatorChar can be any character like comma or semicolon etc. 
//it also allows single quotes inside the string value: e.g. "Mike's Kitchen","Jane's Room"
Regex regx = new Regex(separatorChar + "(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))"); 
string[] line = regx.Split(string to split);

although I too like a challenge some of the time, but this actually isn't one. please read this article http://secretgeek.net/csv_trouble.asp and then go on and use http://www.filehelpers.com/

[Edit1, 3]: or maybe this article can help too (the link only shows some VB.Net sample code but still, you can use it with C# too!): http://msdn.microsoft.com/en-us/library/cakac7e6.aspx

I've tried to do the sample for C# (add reference to Microsoft.VisualBasic to your project)

using System;
using System.IO;
using Microsoft.VisualBasic.FileIO;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            TextReader reader = new StringReader("('ABCDEFG', 123542, 'XYZ 99,9')");
            TextFieldParser fieldParser = new TextFieldParser(reader);

            fieldParser.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited;
            fieldParser.SetDelimiters(",");

            String[] currentRow; 

            while (!fieldParser.EndOfData)
            {
                try
                {
                     currentRow = fieldParser.ReadFields();

                     foreach(String currentField in currentRow)
                     {
                        Console.WriteLine(currentField);                        
                     }
                }
                catch (MalformedLineException e)
                {
                    Console.WriteLine("Line {0} is not valid and will be skipped.", e);
               }

            } 

        }
    }
}

[Edit2]: found another one which could be of help here: http://www.codeproject.com/KB/database/CsvReader.aspx

-- reinhard