/*
 * ExecPgm.java 
 * ------------
 *
 * Descricao: Executa programa passado como argumento na linha de
 *            comando e captura a saida da execucao do comando de 
 *            stdout caso o programa tenha terminado sem erro ou
 *            de stderr caso o programa tenha terminado anormalmente
 *            veja metodo: Process.waitFor()
 *
 *            Exemplo: java ExecPgm ecoa alo .... 
 *
 *            O programa dos ecoa.c exibe os parametros recebidos na
 *            linha de comando e termina NORMALMENTE quando o numero
 *            de argumentos for par e ANORMALMENTE quando for impar
 *            veja ecoa.c
 *
 * @author  ismael h f santos - Created on 22 de junho de 2002
 *
 * @email   ismael@tecgraf.puc-rio.br
 */
import java.io.*;

public class ExecPgm {
	   
  public static void main( String args[] ) {
     // get the runtime object associated with the current Java application.	
     Runtime r = Runtime.getRuntime(); 
     
     // Executes the specified command and arguments in a separate process 
     // Example: java ExecPgm ecoa ....
     if( args.length > 0 ) {
	     PrintWriter out = new PrintWriter( System.out, true );
       out.print("==> Executing command:" );
	     for(int i=0; i<args.length; ++i )
       	  out.print(" " + args[i]);
       out.println("\n");  
     	 try {
          Process p = r.exec(args, null);
          
   	     BufferedWriter toPgm  = new BufferedWriter( 
     	                           new OutputStreamWriter(p.getOutputStream()));
     	   BufferedReader fromPgm= new BufferedReader( 
     	                           new InputStreamReader(p.getInputStream()));
     	   BufferedReader fromErrPgm= new BufferedReader( 
     	                              new InputStreamReader(p.getErrorStream()) );
     	                           
     	  // Calls the command & wait for termination
     	  int ret=0, bytesRead;
          char[] result = new char[256];
          if( (ret=p.waitFor()) == 0 ) {
       	    out.println("==> NORMAL termination retCode=" + ret );
            while( true ) {
              if( (bytesRead=fromPgm.read(result)) == -1 )
                break;
              out.write(result, 0, bytesRead);	      
            }   	
          }	
          else {
       	    out.println("==> ABNORMAL termination retCode=" + ret );
            while( true ) {
              if( (bytesRead=fromErrPgm.read(result)) == -1 )
                break;
              out.write(result, 0, bytesRead);	      
            }   	
          }	     	                           
          out.flush();
        }
        catch( InterruptedException e ) {
          e.printStackTrace();	
        }  
        catch( IOException e ) {
          e.printStackTrace();	
        }  
    }
   }	
}