// Program to print out all the files and subdirectories within
//   a given directory and all of its subdirectories.

import java.util.*;
import java.io.*;

public class FileCrawler {
   public static void main(String[] args) {
      Scanner console = new Scanner(System.in);
      System.out.print("File or directory name? ");
      String name = console.nextLine();
      
      File file = new File(name);
      if (!file.exists()) {
         System.out.println("That file/directory does not exist.");
      } else {
         crawl(file);
      }
   }
   
   // pre: file points to a file or directory that exists
   //      
   // list out all the files in the directory named by file and
   //   all of its subdirectories, indented by depth
   public static void crawl(File file) {
      crawl(file, 0);
   }
   
   // pre: file points to a file or directory that exists
   //      level >= 0
   //
   // list out all the files in the directory named by file
   // if file is not a directory, just print its name
   // otherwise, print all files within the directory and all its
   //   subdirectories, indenting to indicated depth
   private static void crawl(File file, int level) {
      for (int i = 0; i < level; i++) {
         System.out.print("  ");
      }
      System.out.println(file.getName());
      if (file.isDirectory()) {
         for (File subFile : file.listFiles()) {
            crawl(subFile, level + 1);
         }
      }
   }
}