April 2010 – Page 2 – Silveira Neto

o ponto de vista de um pastel de vento

Published by Silveira on 2010-04-14

Life = Risk

Published by Silveira on 2010-04-12

A simple and beautiful video about the early failures, things and people that tries to put you down and we have to face before achieve what we really want.

“If you never failed, you never lived”

Default Password List

Published by Silveira on 2010-04-08

Take a look at http://www.phenoelit-us.org/dpl/dpl.html. The weakest part of a network nowadays, a unconfigured wireless router.

calling commands in Java

Published by Silveira on 2010-04-08

I don’t like the approach of calling native shell commands in any language instead of using multi platform libraries, but here is a little prof of concept Java program to call native commands.

import java.io.*;
import java.util.*;
public class Exec {
   public static void main(String args[]) throws IOException {
      Process proc = Runtime.getRuntime().e xec(args);
      BufferedReader br = new BufferedReader(new InputStreamReader(proc.getInputStream()));
      String line;
      while ((line = br.readLine()) != null) {
         System.out.println(line);
      }
   }
}

Usage:

java Exec VALID_COMMAND

Example:

$ java Exec echo hello
hello

ps: I had to write “e xec” instead of exec because it was triggering some very strange security protection in the blog engine here. If you need to compile this code change that. =P Also there’s no error handling, you should pass a valid command when executing this code.

Iterating over a HashMap

Published by Silveira on 2010-04-08

Iterating over a HashMap using the enhanced loop (foreach) in Java is a good way to keep your code smaller, more legible and usually more semantically coherent.

import java.util.HashMap;
import java.util.Map;

class Foo {}

public class Main {
	
   public static void main(String args[]){
      Map mHash;
		
      mHash = new HashMap();
      mHash.put((byte)1, new Foo());
      mHash.put((byte)2, new Foo());
      mHash.put((byte)3, new Foo());
		
      for(Foo f: mHash.values()){
         System.out.println(f.toString());
      }
   }
}