Return rcvar

    .. versionchanged:: 2016.3.4

    Support for jail (representing jid or jail name) keyword argument in kwargs

def _get_rcvar(name, jail=None):
    '''
    Return rcvar

    .. versionchanged:: 2016.3.4

    Support for jail (representing jid or jail name) keyword argument in kwargs
    '''
    if not available(name, jail):
        log.error('Service %s not found', name)
        return False

    cmd = '{0} {1} rcvar'.format(_cmd(jail), name)

    for line in __salt__['cmd.run_stdout'](cmd, python_shell=False).splitlines():
        if '_enable="' not in line:
            continue
        rcvar, _ = line.split('=', 1)
        return rcvar

    return None