conditional_file.cs

public void Main()
{
    // Create a logical file object 
    System.IO.FileInfo theFile = new System.IO.FileInfo(Dts.Variables["vFilename"].Value.ToString());

    // If the update date on the file is greater than the date specified in the MinDateStamp
    //  variable, set the variable flag to process the file.    
    if (theFile.Exists
        && theFile.LastWriteTime > DateTime.Parse(Dts.Variables["pMinDateStamp"].Value.ToString()))
    {
        Dts.Variables["vProcessFile"].Value = true;

        // Log the processed file
        bool fireAgain = false;
        Dts.Events.FireInformation(0, "SCR - Check file timestamp", "Processed file " + Dts.Variables["vFilename"].Value.ToString()
                                    , null, 0, ref fireAgain);
    }
    else
    {
        // If the updated date is before the date specified, do not process.
        Dts.Variables["vProcessFile"].Value = false;
    }

    Dts.TaskResult = (int)ScriptResults.Success;
}