Extracting specific rows in a CSV file based on a certain prefix-CodePudding

I am attempting to read multiple CSV files in a directory, process and filter these appropriately based on a specific prefix using c#. I then want to write each row to a new CSV file that contains that prefix. The CSV header remains the same.

For example, I have a CSV file before processing as such:

If there is a prefix in a row starting with BAK as an example I want to extract all rows of data to a new CSV file that have that prefix, so my CSV would then look like this. Note that the prefix may not always be in the same place.

CSV after processing:

I have looked at other questions and answers and feel these do not address my question.

What I have so far (C#):

static void Main(string[] args) {
    string sourceDirectory = @"C:\temp\csvfiles\";
    var csvFiles = Directory.EnumerateFiles(sourceDirectory, "*.csv", SearchOption.AllDirectories);
    foreach (string currentFile in csvFiles) {
        //How do I read in only the specfic rows that I need containing certain prefixes
    }
}

CodePudding user response：

You will need to read and parse each row of your input file and then inspect the data to determine if it should be written to the output file.

I don't know how much experience you have parsing CSV files though. There are many available that would make short work of this. May I recommend my own CsvParser?

CodePudding user response：

    static void Main(string[] args)
    {

        string sourceDirectory = @"C:\temp\csvfiles\";
        var csvFiles = Directory.EnumerateFiles(sourceDirectory, "*.csv", SearchOption.AllDirectories);
        foreach (string currentFile in csvFiles)
        {
            //How do I read in only the specfic rows that I need containing certain prefixes
            foreach (string line in File.ReadAllLines(currentFile).Where(m => m.Split(';').Last().Contains("BAK")))
            {
                Console.WriteLine(line);
            }
        }
    }