def ps(self):
        """
        Get the process information from the system PS command.
        """
        
        # Get the process ID
        pid = self.get()
        
        # Parent / child processes
        parent   = None
        children = []
        
        # If the process is running
        if pid:
            proc   = Popen(['ps', '-ef'], stdout=PIPE)
            for _line in proc.stdout.readlines():
                line = self.unicode(_line.rstrip())
                
                # Get the current PID / parent PID
                this_pid, this_parent = self._ps_extract_pid(line)
                try:
                    
                    # If scanning a child process
                    if int(pid) == int(this_parent):
                        children.append('{}; [{}]'.format(this_pid.rstrip(), re.sub(' +', ' ', line)))
                    
                    # If scanning the parent process
                    if int(pid) == int(this_pid):
                        parent = re.sub(' +', ' ', line)
                        
                # Ignore value errors
                except ValueError:
                    continue
                
        # Return the parent PID and any children processes
        return (parent, children)
Get the process information from the system PS command.