Prevent 2 instances of POISE from running simultaneously about nmrpoise HOT 2 CLOSED

backend = subprocess.Popen(...)
backend.pid
...
print(os.getpid(), file=lock_file)  # backend must delete it after it's done

def kill_pid(pid):
    from java.lang.System import getProperty
    # Windows
    if "wind" in getProperty("os.name").lower():
        os.system("taskkill /f /pid {}".format(pid))
    # *nix
    else:
        os.system("kill -9 {}".format(pid))