Command line program execution problem.

Question

Hey there, I'm about to complete my Java thesis project, but I can't fix a problem: i have to find a command line programme (which is in python but i think its not a big deal) through a java programme. Getting some information around I ended up i could execute the program with the command:
Process proc = Runtime.getRuntime().exec("...");
and create the streams:
OutputStream out = proc.getOutputS 14.49
InputStream in = proc.getInputStream();
the problem is that calling a programme which prints on screen something and then it ends (ex. ipconfig) the following sequence works out:
do
int i=in.read();
if(i==-1) break;
System.out.print((char)i);
}while(true);
instead in the specific case of the programme that i need to execute it canno't work because this programme after its opening prints a couple of lines, at this stage you need to type the input in and when the eof font is sent the output is printed. i've tried to send the input thru OutputStream but the execution gets stuck when it reads the output (in.read());
Can you guys help me out? What do i need to do? Please it's very important, let me know ASAP.
Thanks very much,
Fabio

Answer 1

I would not recommend the use of raw "InputStream" for much of anything.
Try Scanner if you can use JDK5, if not, try BufferedReader.
Scanner:
Process proc = Runtime.getRuntime().exec("...");
BufferedOutputStream out = new BufferedOutputStream(proc.getOutputStream());
Scanner in = new Scanner(proc.getInputStream());
while(in.hasNextLine()) {
     String s = in.nextLine();
     System.out.println(s);
}BufferedReader:
Process proc = Runtime.getRuntime().exec("...");
BufferedOutputStream out = new BufferedOutputStream(proc.getOutputStream());
BufferedReader in = new BufferedReader(new InputStreamReader(proc.getInputStream()));
String l = " ";
while(l != null) {
     l = r.nextLine();
     System.out.println(s);
}