Problems with Runtime.getRuntime().exe and getting output. Please Help me!!

Question

I'm creating a program that runs the followings programs written in C and compiled with gcc:
==========================The first C program====================================
#include<stdio.h>
void leia();
main()
int x = 20;
int y = 2;
printf( "Marcinho e Danny\n" );
printf( "Te\n" );
printf( "Vida\n" );
printf( "Marciorja: %d.\n", x * y );
===============================================================================
==========================The second C program====================================
#include<stdio.h>
void leia();
main()
int x = 20;
int y = 2;
printf( "Marcinho e Danny\n" );
printf( "Te\n" );
printf( "Vida\n" );
printf( "Marciorja: %d.\n", x * y );
scanf( "%d", &x ); //This is the statement added to the latter C program.
===============================================================================
I compiled this C program and generates the a.exe program. I have the following Java program:
==================================================================================
import java.awt.Color;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import javax.swing.JFrame;
import javax.swing.text.BadLocationException;
import javax.swing.text.EditorKit;
import javax.swing.text.MutableAttributeSet;
import javax.swing.text.Style;
import javax.swing.text.StyledDocument;
import javax.swing.text.StyledEditorKit;
public class Teste
private BufferedWriter out;
private BufferedReader in;
private Style stylePrompt;
private LeitorDeEntrada le;
private String entrada = "";
private AreaDeEdicao areaDeTexto;
Process p = null;
public Teste( AreaDeEdicao areaDeTexto )
this.areaDeTexto = areaDeTexto;
public void runCommand( String command ) throws IOException
StringTokenizer strTokenizer = new StringTokenizer( command );
String mainCommand = null;
String argument = null;
StyledDocument doc = areaDeTexto.getStyledDocument( );
String[] prefix = new String[] { "cmd.exe", "/c", command };
p = Runtime.getRuntime().exec( prefix, null, new File( System.getProperty( "user.dir" ) ) );
in = new BufferedReader( new InputStreamReader( p.getInputStream( ) ) );
out = new BufferedWriter( new OutputStreamWriter( p.getOutputStream( ) ) );
out.flush();
Thread t = new Thread( )
public void run( )
super.setName( "Marcio" );
execute( );
public void execute( )
String c = null;
try
if( !in.ready( ) )
try
this.sleep( 1000 );
catch( InterruptedException e2 )
e2.printStackTrace( );
System.out.println( "in.rea: " + in.ready( ) );
c = in.readLine( );
catch( IOException e )
e.printStackTrace( );
String str = "";
while( c != null )
str = c + "\n";
try
areaDeTexto.getDocument( ).insertString( areaDeTexto.getDocument( )
.getLength( ),
str, null );
catch( BadLocationException e3 )
e3.printStackTrace( );
try
c = in.readLine( );
catch( IOException e2 )
e2.printStackTrace( );
areaDeTexto.setCaretPosition( areaDeTexto.getDocument( )
.getLength( ) );
try
in.close( );
catch( IOException e1 )
e1.printStackTrace( );
t.setDaemon( true );
t.start( );
le = new LeitorDeEntrada( );
areaDeTexto.addKeyListener( le );
public static void main( String[] args )
JFrame janela = new JFrame( );
AreaDeEdicao areaDeTexto = new AreaDeEdicao( new MyDocument( ) );
areaDeTexto.setBackground( Color.black );
areaDeTexto.setForeground( Color.GREEN );
janela.getContentPane( ).add( areaDeTexto );
Teste teste = new Teste( areaDeTexto );
try
teste.runCommand( "a.exe" );
catch( IOException e )
e.printStackTrace( );
janela.setSize( 500, 300 );
janela.setVisible( true );
class LeitorDeEntrada extends KeyAdapter
public void keyPressed( KeyEvent e )
char c = e.getKeyChar( );
System.out.println( "keyPressed" );
try
if( c == '\n' )
areaDeTexto.getDocument().insertString( areaDeTexto.getDocument( )
.getLength( ),
c + "", null );
out.write( c + "" );
out.flush();
catch( BadLocationException e2 )
e2.printStackTrace( );
} catch (IOException e2) {
e2.printStackTrace();
==================================================================================
This Java program is very simple. It runs the a.exe using the method Runtime.getRuntime().exec and gets input for a.exe from a JTextPane and shows the output in the same JTextPane.
If my a.exe represents the binary code of the first C program the text in the JTextPane is the correct output of the a.exe. But, if my a.exe represents the binary code of the second C program, the JTextPane shows the messages ( "Marcinho e Danny\n", "Te\n", "Vida\n", "Marciorja: %d.\n") after I enter the value claimed by the scanf.
I tested my Java program running programs that require input and all have the same behavior:.
What can I need to do to solve this bug?
I read other posts with the same problem and nobody answers what is the problem.
I'LL pay 10 Duke dollars to the first that answers me.

Answer 1

The second C program with the statement fflush( stdout ) produces the right output.
#include<stdio.h>
void leia();
main()
int x = 20;
int y = 2;
printf( "Marcinho e Danny\n" );
printf( "Te\n" );
printf( "Vida\n" );
fflush( stdout ); //added statement.
printf( "Marciorja: %d.\n", x * y );
scanf( "%d", &x ); //This is the statement added to the latter C program.
but what can I do to run C programs that doesn't flush the stdout?