ExecDemo shows how to execute an external program
import java.io.*;
/**
* ExecDemo shows how to execute an external program (in this case
* the UNIX directory lister /bin/ls) and read its output.
*/
public class ExecDemoLs {
/** The program to run */
public static final String PROGRAM = "ls"; // "dir" for Windows
/** Set to true to end the loop */
static boolean done = false;
public static void main(String argv[]) throws IOException {
final Process p; // Process tracks one external native process
BufferedReader is; // reader for output of process
String line;
p = Runtime.getRuntime().exec(PROGRAM);
// Optional: start a thread to wait for the process to terminate.
// Don't just wait in main line, but here set a "done" flag and
// use that to control the main reading loop below.
Thread waiter = new Thread() {
public void run() {
try {
p.waitFor();
} catch (InterruptedException ex) {
// OK, just quit.
return;
}
System.out.println("Program terminated!");
done = true;
}
};
waiter.start();
// getInputStream gives an Input stream connected to
// the process p's standard output (and vice versa). We use
// that to construct a BufferedReader so we can readLine() it.
is = new BufferedReader(new InputStreamReader(p.getInputStream()));
while (!done && ((line = is.readLine()) != null))
System.out.println(line);
return;
}
}
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