Question

I’m using the A Fast CSV Reader library for reading CSV files in my C# application. However I’m having some trouble with creating the CsvReader object.

CsvReader csv = new CsvReader(new StreamReader("data.csv"), true));

When passing a binary file to this code no exception is thrown and the input file is treated as a normal CSV file. How can I detect if the given file is a CSV file? Or at least how can I make sure that it is not a binary file?

Answer 1

Detecting if a file is text or binary is hard. It also stands to reason that the vast majority of text files are also not CSV. As such, I question whether this validation is worthwhile.

If the CSV reader can’t detected trash inputs (perhaps when you start the parse rather than at construction), then I’d consider a different implementation. There are loads to choose from.

Here’s one available in .net:

Reference Microsoft.VisualBasic and you can use TextFieldParser

using (var parser =
    new TextFieldParser(@"c:\data.csv")
        {
            TextFieldType = FieldType.Delimited,
            Delimiters = new[] { "," }
        })
{
    while (!parser.EndOfData)
    {
        string[] fields;
        fields = parser.ReadFields();
        //go go go!
    }
}