Csharp/C Sharp/Development Class/Parse

Regular Expressions: More Complex Parsing

<source lang="csharp"> /* A Programmer"s Introduction to C# (Second Edition) by Eric Gunnerson Publisher: Apress L.P. ISBN: 1-893115-62-3

• /

// 17 - Strings\Regular Expressions\More Complex Parsing // copyright 2000 Eric Gunnerson // file=logparse.cs // compile with: csc logparse.cs using System; using System.Net; using System.IO; using System.Text.RegularExpressions; using System.Collections; public class MoreComplexParsing {

   public static void Main(string[] args)
   {
       if (args.Length  == 0) //we need a file to parse
       {
           Console.WriteLine("No log file specified.");
       }
       else 
       ParseLogFile(args[0]);
   }
   public static void ParseLogFile(string    filename)
   {
       if (!System.IO.File.Exists(filename))
       {
           Console.WriteLine ("The file specified does not exist.");
       }
       else 
       {
           FileStream f = new FileStream(filename, FileMode.Open);
           StreamReader stream = new StreamReader(f);
           
           string line;
           line = stream.ReadLine();    // header line
           line = stream.ReadLine();    // version line
           line = stream.ReadLine();    // Date line
           
           Regex    regexDate= new Regex(@"\:\s(?<date>[^\s]+)\s");
           Match    match = regexDate.Match(line);
           string    date = "";
           if (match.Length != 0)
           date = match.Groups["date"].ToString();
           
           line = stream.ReadLine();    // Fields line
           
           Regex    regexLine = 
           new Regex(        // match digit or :
           @"(?(\d|\:)+)\s" +
           // match digit or .
           @"(?<ip>(\d|\.)+)\s" +
           // match any non-white
           @"(?<method>\S+)\s" +
           // match any non-white
           @"(?<uri>\S+)\s" + 
           // match any non-white
           @"(?<status>\d+)");
           
           // read through the lines, add an 
           // IISLogRow for each line
           while ((line = stream.ReadLine()) != null)
           {
               //Console.WriteLine(line);
               match = regexLine.Match(line);
               if (match.Length != 0)
               {
                   Console.WriteLine("date: {0} {1}", date, 
                   match.Groups["time"]);
                   Console.WriteLine("IP Address: {0}", 
                   match.Groups["ip"]);
                   Console.WriteLine("Method: {0}", 
                   match.Groups["method"]);
                   Console.WriteLine("Status: {0}", 
                   match.Groups["status"]);
                   Console.WriteLine("URI: {0}\n", 
                   match.Groups["uri"]);
               }
           }
           f.Close();
       }
   }

}

      </source>