run a command on the remote host

def exec_command(self, cmd, tmp_path, sudo_user,sudoable=False, executable='/bin/sh'):
        ''' run a command on the remote host '''

        ssh_cmd = self._password_cmd()
        ssh_cmd += ["ssh", "-tt", "-q"] + self.common_args + [self.host]

        if not self.runner.sudo or not sudoable:
            if executable:
                ssh_cmd.append(executable + ' -c ' + pipes.quote(cmd))
            else:
                ssh_cmd.append(cmd)
        else:
            sudocmd, prompt = utils.make_sudo_cmd(sudo_user, executable, cmd)
            ssh_cmd.append(sudocmd)

        vvv("EXEC %s" % ssh_cmd, host=self.host)
        try:
            # Make sure stdin is a proper (pseudo) pty to avoid: tcgetattr errors
            import pty
            master, slave = pty.openpty()
            p = subprocess.Popen(ssh_cmd, stdin=slave,
                                 stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            stdin = os.fdopen(master, 'w', 0)
        except:
            p = subprocess.Popen(ssh_cmd, stdin=subprocess.PIPE,
                                 stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            stdin = p.stdin

        self._send_password()

        if self.runner.sudo and sudoable and self.runner.sudo_pass:
            fcntl.fcntl(p.stdout, fcntl.F_SETFL,
                        fcntl.fcntl(p.stdout, fcntl.F_GETFL) | os.O_NONBLOCK)
            sudo_output = ''
            while not sudo_output.endswith(prompt):
                rfd, wfd, efd = select.select([p.stdout], [],
                                              [p.stdout], self.runner.timeout)
                if p.stdout in rfd:
                    chunk = p.stdout.read()
                    if not chunk:
                        raise errors.AnsibleError('ssh connection closed waiting for sudo password prompt')
                    sudo_output += chunk
                else:
                    stdout = p.communicate()
                    raise errors.AnsibleError('ssh connection error waiting for sudo password prompt')
            stdin.write(self.runner.sudo_pass + '\n')
            fcntl.fcntl(p.stdout, fcntl.F_SETFL, fcntl.fcntl(p.stdout, fcntl.F_GETFL) & ~os.O_NONBLOCK)

        # We can't use p.communicate here because the ControlMaster may have stdout open as well
        stdout = ''
        stderr = ''
        while True:
            rfd, wfd, efd = select.select([p.stdout, p.stderr], [], [p.stdout, p.stderr], 1)
            if p.stdout in rfd:
                dat = os.read(p.stdout.fileno(), 9000)
                stdout += dat
                if dat == '':
                    p.wait()
                    break
            elif p.stderr in rfd:
                dat = os.read(p.stderr.fileno(), 9000)
                stderr += dat
                if dat == '':
                    p.wait()
                    break
            elif p.poll() is not None:
                break
        stdin.close() # close stdin after we read from stdout (see also issue #848)

        if p.returncode != 0 and stderr.find('Bad configuration option: ControlPersist') != -1:
            raise errors.AnsibleError('using -c ssh on certain older ssh versions may not support ControlPersist, set ANSIBLE_SSH_ARGS="" (or ansible_ssh_args in the config file) before running again')

        return (p.returncode, '', stdout, stderr)