Process Builder waitFor() issue and Open file limitations

Question

I have inherited some code:

Process p = new ProcessBuilder(\"/bin/chmod\", \"777\", path).start();
p.waitFor();

Basically, there is for som

Answer 1

I presume you are running these chmod commands in a loop - otherwise I don't see why you'd get so many exceptions. It's possible that you're hitting a deadlock because you're not reading the output of the spawned processes. That certainly used to bite me back in the pre-ProcessBuilder, Runtime.exec() days.

Change your code snippet to the above pattern:

try {
    ProcessBuilder pb = new ProcessBuilder("/bin/chmod", "777", path);    
    pb.redirectErrorStream(true); // merge stdout, stderr of process

    Process p = pb.start();
    InputStreamReader isr = new  InputStreamReader(p.getInputStream());
    BufferedReader br = new BufferedReader(isr);

    String lineRead;
    while ((lineRead = br.readLine()) != null) {
        // swallow the line, or print it out - System.out.println(lineRead);
    }

    int rc = p.waitFor();
    // TODO error handling for non-zero rc
}
catch (IOException e) {
    e.printStackTrace(); // or log it, or otherwise handle it
}
catch (InterruptedException ie) {
    ie.printStackTrace(); // or log it, or otherwise handle it
} 

(credit: this site) and see if that helps the situation.