CsvHelper : How to detect the Delimiter from the given csv file

Question

I am using CsvHelper to read/writer the data into Csv file. Now I want to parse the delimiter of the csv file. How can I get this please?

My code:

     var parser = new CsvParser(txtReader);
     delimiter = parser.Configuration.Delimiter;

I always got delimiter is "," but actually in the csv file the delimiter is "\t".

Answer 1

Since I had to deal with the possibility that, depending on the localization settings of the user, the CSV file (Saved in MS Excel) could contain a different delimiter, I ended up with the following approach :

public static string DetectDelimiter(StreamReader reader)
{
    // assume one of following delimiters
    var possibleDelimiters =  new List<string> {",",";","\t","|"};

    var headerLine = reader.ReadLine();

    // reset the reader to initial position for outside reuse
    // Eg. Csv helper won't find header line, because it has been read in the Reader
    reader.BaseStream.Position = 0;
    reader.DiscardBufferedData();

    foreach (var possibleDelimiter in possibleDelimiters)
    {
        if (headerLine.Contains(possibleDelimiter))
        {
            return possibleDelimiter;
        }
    }

    return possibleDelimiters[0];
}

I also needed to reset the reader's read position, since it was the same instance I used In the CsvReader constructor.

The usage was then as follows:

using (var textReader = new StreamReader(memoryStream))
{
    var delimiter = DetectDelimiter(textReader);

    using (var csv = new CsvReader(textReader))
    {
        csv.Configuration.Delimiter = delimiter;

        ... rest of the csv reader process

    }
}