/** 
 * EnumLines - Annotate input with lines and filenames
 * Good for testing out new Java installations, and suchlike. 
 * License: GPL 2; share and enjoy!
 * @author Sean B. Palmer, inamidst.com
 * @version 0.1
 */

package com.inamidst.jmisc; 

import java.io.BufferedReader; 
import java.io.FileReader; 

public class EnumLines { 
   String fn; 
   final String usage = "java com.inamidst.jmisc.EnumLines <file>"; 

   /** 
    * fromFilename - Enumerate a file from its filename. 
    * @param fn Filename to read from. 
    */
   public void fromFilename(String fn) {
      this.fn = fn; 
      try { enumerate(); }
      catch (Exception e) { barf(e.getMessage()); }
   }

   /** Enumerate a file from currently set filename. */
   public void enumerate() throws Exception { 
      String line; 
      int n = 0; 

      BufferedReader reader = new BufferedReader(new FileReader(fn)); 
      while ((line = reader.readLine()) != null) {
         n++; System.out.println(fn + ":" + n + ":" + line); 
      }
   }

   /** 
    * Display an error message for a given filename
    * @param msg Error message
    */
   public void barf(String msg) {
      System.err.println("E: " + msg + ": " + this.fn); 
      System.exit(1); 
   }

   /** 
    * Reads filenames from argv and outputs lines annotated 
    * with filename and line.
    * @param args ARGV[1:].
    */
   public static void main(String [] args) {
      EnumLines enum = new EnumLines(); 
      if (args.length != 1) 
         System.out.println("Usage: " + enum.usage); 
      else { enum.fromFilename(args[0]); }
   }

}