Re: broken pipe

Dear Gordon,
Thank you very much that you had a close look on my code example.
Unfortunately I have no source code of the 4bol interpreter. I can only
observe what it is doing when invoked on a text terminal. And then it
definitely accepts more input after a parse error.

What can be happening in 4bol during or after a parse error?
Is it possible that the 4bol process closes it's input pipe and opens a
new one? And does my java class have a chance to update it's
BufferedWriter out when this happens?
Is it possible that 4bol continues as a new thread which has a new
input pipe?

As to your suggestions on listen(), I changed the "new Thread()" calls
as follows:
--- source fragment ---
       new Thread(){
            public void run(){
                try {
                    String line;
                    while(true){
                        line = in.readLine();
                        if (line!=null)
                            System.out.println("STD: "+line);
                        else {
                         System.out.println("STD: READ NULL"); // for
debug only
                         sleep(2000);
                        }
                    }
                } catch (IOException e){ System.err.println(e);}
                catch (InterruptedException e){ System.err.println(e);}
            }
        }.start();
 --- end ---
similar for err, accordingly, and there is only one call to listen()
left. (I wanted to have it this simple from the beginning. But some bug
let me only send one command and receive one result.)

Now the result is the basically the same as with multiple listen():
--- output ---
 STD: Welcome to the 4bol test assembler
move 4
STD: 4
add 3
STD: 7
mult 2
ERR: parse error: mult 2ERR: READ NULL

STD: READ NULL
ERR: READ NULL
STD: READ NULL
ERR: READ NULL
STD: READ NULL (repeated every 2000ms)
move 4
java.io.IOException: Broken pipe
[...]
        at oboe.XProcess.command(XProcess.java:56)
        at oboe.XProcess.main(XProcess.java:77)
ERR: READ NULL
STD: READ NULL
ERR: READ NULL
STD: READ NULL
[...]
--- end ---

Does this output give any new insight on what might be happening, or
can you imagine why 4bol remains active in the terminal but closes it's
input pipe in the java program?

Thanks
Norbert