Name: ap32198 Date: 10/29/98


The following java program performed interactions with
the exec'd process at a rate of about 1000/sec under 1.0.
This dropped to about 1/sec with 1.1.

I assume the problem is some sort of timeout on the
in.read() call.


JAVA code ------------------------------------------------

import java.io.*;



/*********************************************************/
/* */
/* EXECTEST */
/* */
/* This simple JAVA program starts an executable */
/* and sends it some strings. The executable */
/* converts the strings to upper case and */
/* encases them in brackets. Upon return reciept, */
/* this routine prints them out. */
/* */
/*********************************************************/


public class ExecTest
{
   public static void main(String[] args)
   {
      int i;
      Service svc;
      String command, response;

      svc = new Service("exectest");

      for(i=0; i<10; ++i)
      {
         command = "testing " + i;

         response = svc.sendCommand(command);

         System.out.println(response);
      }

      svc.endProcess();
   }
}



/*********************************************************/
/* */
/* SERVICE: This class has methods to start an */
/* executable, send it a command and get a response, */
/* and kill the child process. */
/* */
/*********************************************************/


class Service
{
   private Runtime runtime = Runtime.getRuntime();
   private Process process;
   private OutputStream out;
   private InputStream in;



   // Creation method. Starts up the executable

   public Service(String executable)
   {
      try
      {
         process = runtime.exec(executable);

         out = process.getOutputStream();
         in = process.getInputStream ();
      }
      catch(IOException e)
      {
         System.err.println("exec error: " + e);
      }
   }


   // Method to send a command and get a response

   public String sendCommand(String command)
   {
      int i, c;
      StringBuffer resp;

      resp = new StringBuffer(4096);

      try
      {
         for(i=0; i<command.length(); ++i)
            out.write((int) command.charAt(i));

         out.write('\n');
         out.flush();

         while((c = in.read()) > -1)
         {
            if((char)c == '\n')
               break;

            resp.append((char)c);
         }
      }
      catch(IOException e)
      {
         System.err.println("exec error: " + e);
      }

      return(resp.toString());
   }


   // Method to kill the child

   public void endProcess()
   {
      process.destroy();
   }
}


C process code ------------------------------------------

#include <stdio.h>
#include <ctype.h>

main()
{
   int i;
   char str[1024];

   while(1)
   {
      if(gets(str) == (char *)NULL)
         break;

      for(i=0; i<strlen(str); ++i)
         if(isalpha(str[i]))
            str[i] = toupper(str[i]);

      fprintf(stdout, "[%s]\n", str);
      fflush(stdout);
   }
}

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(Review ID: 41485)
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