Question

I have an array of strings from a log file with the following format:

var lines = new []
{
    "--------",
    "TimeStamp: 12:45",
    "Message: Message #1",
    "--------",
    "--------",
    "TimeStamp: 12:54",
    "Message: Message #2",
    "--------",
    "--------",
    "Message: Message #3",
    "TimeStamp: 12:55",
    "--------"
}

I want to group each set of lines (as delimited by "--------") into a list using LINQ. Basically, I want a List<List<string>> or similar where each inner list contains 4 strings – 2 separators, a timestamp and a message.

I should add that I would like to make this as generic as possible, as the log-file format could change.

Can this be done?

Answer 1

Will this work?

var result = Enumerable.Range(0, lines.Length / 4)
                       .Select(l => lines.Skip(l * 4).Take(4).ToList())
                       .ToList()

EDIT:

This looks a little hacky but I’m sure it can be cleaned up

    IEnumerable<List<String>> GetLogGroups(string[] lines)
    {
        var list = new List<String>();
        foreach (var line in lines)
        {
            list.Add(line);
            if (list.Count(l => l.All(c => c == '-')) == 2)
            {
                yield return list;
                list = new List<string>();
            }
        }
    }