How do I handle line breaks in a CSV file using C#?

Question

I have an Excel spreadsheet being converted into a CSV file in C#, but am having a problem dealing with line breaks. For instance:

\"John\",\"23\",\"555-555         


        

Answer 1

Rather than check if the current line is missing the (") as the first character, check instead to see if the last character is a ("). If it is not, you know you have a line break, and you can read the next line and merge it together.

I am assuming your example data was accurate - fields were wrapped in quotes. If quotes might not delimit a text field (or new-lines are somehow found in non-text data), then all bets are off!

Answer 2

A somewhat simple regular expression could be used on each line. When it matches, you process each field from the match. When it doesn't find a match, you skip that line.

The regular expression could look something like this.

Match match = Regex.Match(line, @"^(?:,?(?<q>['"](?<field>.*?\k'q')|(?<field>[^,]*))+$");
if (match.Success)
{
  foreach (var capture in match.Groups["field"].Captures)
  {
    string fieldValue = capture.Value;
    // Use the value.
  }
}