Grab CloudCompare Command Line Output with Java ProcessBuilder

Question

I'm playing a bit around with a small JAVA gui for the command line mode of cloudcompare .

Therefore I'm using a short snippet like these:

var processBuilder = new ProcessBuilder();
try {
    var process = processBuilder
             .command("open", "-a", "CloudCompare.app", "-n",
                      "--args", "-NO_TIMESTAMP", "-C_EXPORT_FMT", "LAS",
                      "-O", "/Users/se/pcl_1.las",
                      "-O", "/Users/se/pcl_2.las",
                      "-MERGE_CLOUDS")
             .start();
    
    String error, line;

    BufferedReader inputStream = new BufferedReader(new InputStreamReader(process.getInputStream()));

    while ((line = inputStream.readLine()) != null) {
        System.out.println("line = " + line);
    }

    BufferedReader errorStream = new BufferedReader(new InputStreamReader(process.getErrorStream()));

    while ((error = errorStream.readLine()) != null) {
       System.out.println("error = " + error);
    }

    var ret = process.waitFor();

    System.out.printf("Program exited with code: %d", ret);

} catch (IOException | InterruptedException e) {
      e.printStackTrace();
}

But if I run it on macOS the command line window opens, the process runs normal, but I can't grab any of the informations in it. There is an option to write log files from cloudcompare. That works - the log file shows that all cloud processing steps are done.

Does anybody knows, how to grab the command line output?

Answer 1

As mentioned here , the /usr/bin/open command is not an option to grab the stdinput stream.

I change the command to /Applications/CloudCompare.app/Contents/MacOS/CloudCompare and it works.

The next question is, how to grab the InputStream with a thread. I tried some stack overflow topics, but it doesn't work at the moment, to get the output stream in realtime. It is flushed at the end of the CloudCompare process.