Processing: popen() call to start subprocess?

Question

Here's an example of opening and reading data from a TCP socket. Is there a a popen() call or equivalent that can start a child process and read its output?

void setup() {
    c = new Client(this, "127.0.0.1", 12345); // Replace with your server's IP and port
}

void draw() {
    if (c.available() > 0) {
        input = c.readString();

http://www.processing.org/learning/libraries/sharedcanvasclient.html