Untitled

static void Main(string[] args)
{
    if (args.Length != 2) return;
    string searchPattern = args[0], dir = Path.GetDirectoryName(args[1]), filePattern = Path.GetFileName(args[1]);
    var files = from file in Directory.EnumerateFiles(dir, filePattern, SearchOption.AllDirectories)
                from line in File.ReadLines(file).Select((text, i) => new { Text = text, Index = i })
                where new Regex(searchPattern).IsMatch(line.Text)
                select new { File = file, LineText = line.Text, LineNo = line.Index };
    Parallel.ForEach(files, (f) => { Console.WriteLine("{0}({1}){2}", f.File, f.LineNo, f.LineText); });
}