def make_system_user(c, name, home=None, uid=None, shell=None):
    """
    Make a new system user account, with the given home folder and shell path.
    """
    if not c.run('getent passwd {}'.format(name), warn=True).failed:
        return
    home = '--home {}'.format(home) if home else ''
    uid = '--uid {}'.format(uid) if uid else ''
    shell = '--shell {}'.format(shell) if shell else ''
    c.sudo('adduser --system --group {} {} {} {}'.format(name, home, uid,
        shell))
