import java.io.File;
import java.io.FilenameFilter;
import java.util.regex.Pattern;


public class Listdirectory {
  public static void main(String[] args) {
    File directorypath = new File("/home/girish/Desktop/Linux");
    String[] list;
    if (args.length == 0)
      list = directorypath.list();
     
    else
      list = directorypath.list(new DirFilter(args[0]));
       for (int i = 0; i < list.length; i++)
      System.out.println(list[i]);
  }
}
 class DirFilter implements FilenameFilter {
  private Pattern pattern;

  public DirFilter(String regex) {
    pattern = Pattern.compile(regex);
  }

  public boolean accept(File directorypath, String name) {
   return pattern.matcher(new File(name).getName()).matches();
  }
}