// Example from Lecture 7: Streams
// remove all punctuation symbols from a text file

using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;

public class DotKill {
  // main worker function, removing all punctuation symbols in file
  public static string removePunctuation(string file) {
    string file0 = file+"0";

    if (File.Exists(file)) {
      using (StreamReader sr = new StreamReader(file)) {    // open file
	using (StreamWriter sw = new StreamWriter(file0)) { // open file
            string str = "";
	    string str0  = "";
            while ((str = sr.ReadLine()) != null) // iterate over all lines
            {
	      str0 = "";
	      foreach (char c in str) {
		if (Char.IsPunctuation(c)) {
		  // nothing
		} else {
		  str0 += c;
		}
	      }
	      sw.WriteLine(str0.ToLower());
	    }
	}
      }
    }
    return file0;
  }

  public static void Main (string[] args) {
     if (args.Length != 1) { // expect 1 args: filename
       System.Console.WriteLine("Usage: files4 <filename>");
     } else {
       string file = args[0];
       DotKill.removePunctuation(file);
       System.Console.WriteLine("Result written to {0}0", file);
     }
  }
}