Fire a cmd.exe command through ProcessBuilder with visual window

Question

I am using this code:

ProcessBuilder builder = new ProcessBuilder("cmd.exe","java","invalidArg");
builder.redirectErrorStream(true);
try {
 Process p = builder.start();
 BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()),10240);
 String line;
 if(processIsTerminated(p)){
 line = r.readLine();
 }
} catch (IOException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
}

Is there a way to have the cmd window open as well when I use the .start() function? Currently it runs hidden and if there is no response I don't know if my command was ran successfully or it didn't run at all.

• Pramod Karandikar: I don't think it's possible, because ProcessBuilder only takes the inputs and passes to the process you pass in the first argument.

Answer 1

Well you have only 2 ways of running a command under Windows :

• the way you go : you have full access to the input, output and error stream of the lauched command, but it has no window and anyway it would not write anything there since your program gets all the output
• ask cmd.exe to start the other command in its own window (and optionnaly wait for its end). But then as the command writes to its own window, you program has no access to the input, output or error streams of the command

You can obtain that 2nd execution way with the start [/w] command arguments command of cmd.exe, just type start /w cmd.exe /c "echo foo & pause" in a cmd window to see what happens (the & pause is only there to let you some time to read the output ...)

From java, it would be :

ProcessBuilder builder = new ProcessBuilder("cmd.exe","/c", "start", "/w",
 "cmd", "/c", "java invalidArg & pause");

• greenfeet: Thanks, I used this method to debug my code and then went back to the prior method in order to have access to the input/output. Ideally I would like to have the window open AND have access to the input/output streams...